Bird's-eye view of a PuzzleScript file

A puzzlescript file is divided into 8 sections:

Prelude

Before any of the "official" sections are declared, you can give details about your project in this section, and also set some editor options.

title 2D Whale World
author increpare
homepage www.increpare.com

require_player_movement
key_repeat_interval 0.12

Here are the possible options:

author increpare

Your name goes here. This will appear in the title screen of the game.

color_palette mastersystem

By default, when you use colour names, they are pulled from a variation of Arne's 16-Colour palette. However, there are other palettes to choose from:

1 - mastersystem
2 - gameboycolour
3 - amiga
4 - arnecolors
5 - famicom
6 - atari
7 - pastel
8 - ega
9 - amstrad
10 - proteus_mellow
11 - proteus_rich
12 - proteus_night
13 - c64
14 - whitingjp

(you can also refer to them by their numerical index)

again_interval 0.1

The amount of time it takes an 'again' event to trigger.

background_color blue

Can accept a color name or hex code (in the form #412bbc). Controls the background color of title/message screens, as well as the background color of the website. Text_color is its sibling.

debug

This outputs the compiled instructions whenever you build your file. For instance, the line

 Edit[ > Player | Crate ] -> [ > Player | > Crate ]

is compiled into four instructions, as the output from debug shows when you hit 'RUN':

===========
Rule Assembly : (4 rules)
===========
  (83) DOWN [ crate | up player ] -> [ up crate | up player ]
+ (83) DOWN [ down player | crate ] -> [ down player | down crate ]
+ (83) RIGHT [ crate | left player ] -> [ left crate | left player ]
+ (83) RIGHT [ right player | crate ] -> [ right player | right crate ]
===========

Going from left to right:

The number near the left is the line-number the rule came from in the original source code. You can click on the number to jump to that line in the file.
A plus-sign on the left of the line indicates that the rule is grouped with the previous one as part of a rule-group and the engine will loop through the group as a whole trying to apply the rules until no more rules in the group can be applied (See the rules page for more info).

The compiler does a lot of stuff to the rules you give to it to 'simplify' them in various ways. One thing it does for instance is replace all relative directions ( ^, v, <, and >), with UP, DOWN, LEFT, and RIGHT, which often involves splitting a single rule into many more rules (as above). An other thing you'll notice is that the core engine has rules only going DOWN and RIGHT - rules in other directions are flipped. For more information about directions in puzzlescript, see this page.

flickscreen WxH

Setting flickscreen divides each level into WxH grids, and zooms the camera in so that the player can only see one at a time - the camera does not follow the player around on a move-to-move basis, but if the player moves from one part of this grid to another, the camera flicks to the new position. See Legend of Zokoban for a cute example.

homepage www.mypage.com

The homepage of the author. This doesn't appear directly in the game itself, but is included in the shared game and exported HTML build.

key_repeat_interval 0.1

When you hold down a key, how long is the delay between repeated presses getting sent to the game (in seconds)? The default value is 1.5.

noaction

Changes the action key (X) instruction from the title screen, and does not respond when the player pressed it (outside of menus and cutscenes and the like).

norepeat_action

For many games, you don't want holding action down to retrigger it - games where you're toggling a switch, say. For these games, set norepeat_action, and the action button will only respond to individual presses.

noundo

Disables the undo key (Z) (I generally advise against disabling undo, FWIW).

norestart

Disables the restart key (R)

realtime_interval

The number indicates how long each realtime frame should be. In the above case, twice a second the game engine will tick, but with no input. Player input is processed as regular. See this documentation for more info on making realtime games.

require_player_movement

This is a common requirement in games - if the player doesn't move, cancel the whole move. This is equivalent, where there's only one player character, to the following:

[ Player ]->[ Player Temp ]
late [ Player Temp ] -> CANCEL
late [ Temp ] -> [ ]

run_rules_on_level_start

For some games you will want, before the player sees the level, for the rules to be applied once. (Games that have rules that generate level graphics on the fly, for instance, may want this. Try out this game with and without the prelude option and compare results.)

scanline

Applies a scanline visual effect - only draws every other line

text_color blue

Can accept a color name or hex code (in the form #412bbc). Controls the font color of title/message screens, as well as the font color in the website. Background_color is its sibling.

title My Amazing Puzzle Game

The name of your game. Appears on the title screen.

throttle_movement

For use in conjunction with realtime_interval - this stops you from moving crazy fast - repeated keypresses of the same movement direction will not increase your speed. This doesn't apply to the action button. If you can think of an example that requires action be throttled, just let me know and I'll try accommodate you.

verbose_logging

As you play the game, spits out information about all rules applied as you play, and also allows visual inspection of what exactly the rules do with the visual debugger.

zoomscreen WxH

Zooms the camera in to a WxH section of the map around the player, centered on the player. Silly example.

New in PS+

There are many new prelude flags in PuzzleScript Plus, allowing you to enable mouse controls, level select, text settings, camera/tweening options, and much more.

Mouse controls (ThatScar)

mouse_left object

If the player clicks on a specific tile of the screen, then this object will be created there before any other rules are done. If you don't specify an object name, it will look for an object called "lmb". Once you add this flag, various things (like the title screen) will change to reflect that the game is mainly mouse-controlled.

mouse_drag object

If the player has clicked and is moving their mouse, it will place this object & start a turn when the cursor moves into a different cell. If you don't specify an object name, it will look for an object called "drag"

mouse_up object

If the player has clicked and is releasing their mouse button, it will place this object then do a turn.

mouse_right, mouse_rdrag, mouse_rup object

Similar to the above three, but for the right mouse button. Note that you can also Ctrl + Left Click to get the right mouse button behaviour in-game.

Level Select (Dario)

level_select

Adding this will add a level select to your game. By default, this will allow the player to play all levels in any order. In order to add entries to the level select, add a section in-between your levels.

continue_is_level_select

Don't show an extra option for the Level Select on the main menu. Instead, the "continue" button will open it, instead of continuing the game.

level_select_lock

Will lock any levels that haven't been solved yet or are next to be solved.

level_select_unlocked_ahead

How many levels to unlock ahead after the last solved level when level_select_lock is on, 1 by default.
If you set it to 3, then section 1, 2, and 3 will be available. If you solve section 2, then you'll unlock 4 and 5. (So there will always be three levels unlocked AFTER the last solved level at max.)

level_select_unlocked_rollover

Alternative to LEVEL_SELECT_UNLOCKED_AHEAD that more strictly limits the number of unsolved levels at any time.
If you set this to 3, then section 1, 2, and 3 will be available at the start. If you solve section 2, then only section 4 will unlock. (So there will only ever be three "unsolved" levels at most.)

level_select_solve_symbol

Which symbol to display for levels that have been solved in the level select. It's a checkmark by default, but you can change it in case you're using a custom_font that doesn't have a checkmark glyph.

Text settings (Dario & PS+)

custom_font data:font/otf;base64,

Allows you to load in a custom font file via a data stream. This works best with monospace fonts & font files with very small sizes (under 20KB). If you have a font file and you want to convert it into base64, use a tool like File to Base64 with the "Data URI" output format, then paste it into the editor.

font_size size

Font size is in em, meaning 1 is the default and is treated as a percentage (e.g. 0.5 is half font size & 2 is double the normal font size). Can only be used with custom_font.

message_text_align left/center/right

How to align text for messages: 'left', 'center' (default), or 'right'. If you need more control over the text layout, you can also use \n to manually add a newline.

Smoothscreen (sftrabbit)

smoothscreen flick WxH IxJ S

Zooms the camera in to a WxH section of the map around the playerand smoothly scrolls to follow the player. The optional argument IxJ (default: 1x1) specifies a boundary in which the player can move without moving the camera. The optional S argument (default: 0.125) specifies how far the camera will move towards the player each frame as a fraction of the distance to the player. Additionally, the optional flick keyword makes the camera move like flickscreen, where the camera always moves the full boundary width/height. To get a smooth version of flick screen, provide the flick keyword and make WxH and IxJ the same dimensions.

smoothscreen_debug

Render debug information about the smoothscreen camera. The red circle and box represent the camera's position and the boundary around it. The blue circle and box are at the position the camera is moving towards. The green circle marks the location of the player that is being followed by the camera.

Runtime Metadata Twiddling (PS+)

runtime_metadata_twiddling

Allows you to change some prelude properties while the game is running using commands. More info here.

runtime_metadata_twiddling_debug

Will log into the console whenever a prelude property is changed.

Local Radius (Jack Lance)

local_radius radius

If you set the local_radius flag to a whole number, then the game will only check rules that are in that amount of tiles (a square radius) around the player (or one of the players if you have multiple players in the level). If you still want to have rules to be checked anywhere on the level, preface them with the global keyword like this:

(Rows of global crates can push each other, even outside of the player radius)
global [> GCrate | GCrate] -> [> GCrate | > GCrate ]

You generally don't need to use this unless you have a really big level, a ton of rules, and your game would otherwise run slowly.

Tweening (PS+)

Although you can animate your game using again, PS+ offers a more generalized method of inbetweening movement you can use instead!
Note that it has a number of limitations. It should work for simple games, but might not be powerful enough for complex games.

tween_length 0.05

Enables tweens for LEFT, RIGHT, UP, and DOWN object movement, and for ACTION (will fade in that object). Tweens will take the duration you specify in seconds An object must execute its movement for this animation to play, currently there is no way to play an animation without moving.
Note that if the next turn starts before this tween is completed, the previous tween instantly completes. For this reason, we recommend setting the tween_length very low, somewhere between 0.05 and 0.075 seconds, but at least lower than the AGAIN_INTERVAL and KEY_REPEAT_INTERVAL, and to avoid using it in games that use REALTIME_INTERVAL. Additionally, late rules can tamped with this system, so it's not recommended to use these rules in games that use LATE rules.

tween_easing easeInQuad

When using TWEEN_LENGTH, you can use these to indicate how the movement should lerp. Just like with COLOR_PALETTE you can use either the name or the number. The following options are valid. (To view these in action, see easings.net).

1: linear (default)
2: easeInQuad
3: easeOutQuad
4: easeInOutQuad
5: easeInCubic
6: easeOutCubic
7: easeInOutCubic
8: easeInQuart
9: easeOutQuart
10: easeInOutQuart
11: easeInQuint
12: easeOutQuint
13: easeInOutQuint

tween_snap 5

By default, the tween will snap to the SPRITE_SIZE to conform to the pixel grid. However, with this prelude you can overwrite this if you want the transition to happen more granually when the canvas is drawn on a large scale. You can even put it to a very high number (like 1000) to make the snapping essentially smoothless.

Misc. (Dario)

case_sensitive

Will force the engine to be case sensitive, to see "a" and "A" or "moved" and "moveD" as different objects.

sprite_size size

Instead of 5x5, this option allows you to pick other square resolutions for your sprites. Do note that all sprites MUST be of this size for the game to display correctly. If you need help with upscaling your sprites, there's a helpful tool available here.

Misc. (PS+)

skip_title_screen

Will skip the title screen when the game initializes. Instead, it will act like the "continue" button has been pressed, opening either the level, message, or level select based on game progress and other prelude flags.

text_controls

Will overwrite the default keyboard/mouse control text in the title screen with the text you specify here! It can display up to three lines of text at once, and supports using \n to add a newline.

text_message_continue

Override the text below MESSAGEs that normally says 'X to continue' or 'Click to continue'.

sitelock_origin_whitelist

Causes your game to only be able to run on websites with the listed origins, separated by whitespaces. An origin is for example https://auroriax.github.io:1234.

sitelock_hostname_whitelist

Causes your game to only be able to run on websites with the listed hostnames, separated by whitespaces. A hostname is for example auroriax.github.io.