RockFall

Make your own levels and contribute them here!

Rules

🙂 Player: A, S, D, W or ⬅️, ➡️, ⬆️, ⬇️ to move
🧧 Exit: Opens when you've collected 'goal' number of diamonds/eggs
🔳 Open Exit: Completes the level
🟫 Dirt: Can be dug
⬜️ Wall: Unmovable, un-diggable, but explodable
🟪 Border: Un-explodable
🌑 Rock: Pushable left or right.
💎 Diamond: 100 points
🦋 Butterfly: Turns left. If something falls on it or it touches an
amoeba 🦠 it explodes into 9 eggs. Deadly to player.
🥚 Egg: Worth 10 points, Hatches into Butterfly
👾 Guardian: Turns right. If something falls on it explodes into
space. Deadly to player.
🦠 Amoeba: Grows. If it reaches 100 Amoeba they all turn to eggs. If it's
surrounded so it can't grow they all turn into diamonds.
🦀 SideWalker: goes only left/right or up/down
🪲 Patroller: only turns when it hits something
🚪 Door: player can pass through but nothing else.
💣 Bomb: explodes when it falls on anything but dirt or when touched by an enemy.
🏧 Magic Wall: The first time something drops on it it turns on. While on, any
rock or egg dropped on it will become a diamond. Any diamond dropped on it
will become a rock. Stops after a few seconds.
🔥 Fire: Burns dirt. Not dangerous to stand next to but you die if you walk in it. Kills Enemies
🎈 Balloon: Floats up, if it hit's spike ⚙️ bursts into diamond.

Rocks, Bombs, Eggs, and Diamonds will fall if there is space below them or if
they are sitting on top of another rock, egg, or diamond and there is space for
them to fall.

You can restart by clicking in the top left corner or select another level by
clicking the name.

Note: You can dig one tile without moving by holding shift.

The first level is random so and there is no real theme so it's just a proof of
concept. In fact given it's random it's possible it's impossible to complete. If
so click the 🔄 icon to generate a new level. If you get stuck you can kill
yourself by clicking the ☠️ icon. Note that having the entrance blocked means
you can't do the level but having the exit blocked may mean you can challenge
yourself to lure some enemies over there and drop rocks on them to mine a way
into the exit 😛

A real game would require hand designed or algorithmically generated levels.

Settings

These settings can be set with query parameters

property	default	description
amoebas	1	number of amoebas
butterflies	5	number of butterflies
diamonds	15	number of diamonds
guards	3	number of guardians
rocks	280	number of rocks
walls	10	number of walls
magicWalls	2	number of magic walls
fire	0	number of fire
balloons	3	number of balloons
bomb	3	number of bombs
sideWalkers	3	number of side walkers
patrollers	3	number of patrollers
maxAmoebas	100	how many amoebas when it turns into eggs
amoebaGrowthRate	200	lower is faster
amoebaMinTicksToGrow	50	Force the amoeba to grow within this many ticks
fireSpreadRate	10	lower is faster
maxFireAge	40	Frames when fire dies (must be less than 63)
magicTime	250	how many ticks the magic walls stay active
tileSize	32	size of tiles (note
scrollRate	0.0125	scroll speed
diamondPoints	100	points for collecting diamond
eggPoints	10	points for collecting egg
dirtPoints	1	points for digging dirt
mapWidth	80	map width in tiles
mapHeight	25	map height in tiles
frameRate	0.1	frame rate in seconds
colorVariation	1	color variation multiplier. Set to 0 for no variation
requiredCount	15	count (eggs + diamonds) needed to open exits
timeLimit	1500	time limit in seconds
maxPushRocks	100000	max rocks that can be pushed
pushTurnsPerRock	1	turns per rock to push (set to 0 for same speed regardless of number of rocks)
minRockPushTurns	1	number of turns until you can start pushing rocks (set to 0 for instant)
canPushWithRocksAbove	true	can push with rocks above
playerBoundsWidthPercent	0.125	size of window to keep player inside
playerBoundsHeightPercent	0.125	size of window to keep player inside
level	0	level to use (see here)

Examples:

larger level
tiny level
small tiles
faster
Magic Wall (built with Tiled)
Hatchery (built with Tiled)

Note: The level parameters only work when level=random

History

In the early 1980s, a game,
BoulderDash came out for the Atari
800. My friend, John and I, got addicted and cleared all the levels.

At some point John tried to reproduce the main logic of the game. He did this in
a language called
Action!.
It's pretty incredible to think someone stuck a language compiler and editor in
a 16k cartridge!

In any case, John got something working. The code was not all that big. As such, over the years I've ported it
several times. I ported it to C at some point. According to the comments that was 1992.

I once ported it to Z80 assembly for the original GameBoy when I was first
learning how it works. I ported it to Java for some feature phone around
2003-2004 to bring to a job interview at Namco Japan for their mobile division.

Recently (March 2022) I was going though some old backups and I saw it sitting there
and decided it might be fun to port it to JavaScript.

My first attempt was to use emoji and Canvas 2D.

After that I thought it would be fun to use the tilemap shader I wrote for
HFT-BoomBoom.

This is the result.

Note: Differences from the original:

In the original, Butterflies explode into diamonds, not eggs. It would probably
be best to make a 3rd enemy that explodes into diamonds for the variety but in
these random levels it's arguably more fun that butterflies explode into eggs so
you can see lots of movement. Also in the original you can only push a single
rock. If 2 or more rocks are in a row they can not be pushed.

Design

Currently the first level is just randomly generated.

For this game to be fun really requires well designed levels. The original Atari
game had 60 or so levels. Each level had themes, a required number of items to
open the exit, and a time limit. In other words, if the level required 40 items
then you'd need to collect 40 diamonds or eggs to open the exit and then make it
to the exit before the time limit.

The first few levels were mostly just rocks, walls, and diamonds. Some levels
had less than the required diamonds but had butterflies so if you dropped rocks
on them they'd generate diamonds. Other levels, some diamonds might be
surrounded by walls so you need to lure guardians next to the walls and drop
rocks on their heads to explode the walls.

Another example was the magic wall. It turns rocks into diamonds but you can
only use it once. So, you'd need to dig around and push as many rocks as
possible into position and also dig out space below the magic wall so that once
you turned it on you could push all the rocks into the magic wall and have them
all turn into diamonds.

Yet another example was having the amoeba at the bottom of some level and you'd
need to find a way to surround it with rocks so that it turned into diamonds
before it grew too big and turned into eggs and then butterflies.

Anyway, all of those are interesting puzzles to solve but they require a level
designer. PRs welcome!

Building levels

See instructions here.

Enhancements / Ideas

At the moment I just used the system's emoji for graphics. Ideally, at a
minimum, someone would draw custom graphics including animated tiles for the gem
spinning, the butterfly flapping, the monsters moving, the amoeba oozing, the
magic wall animating, the egg hatching, explosions.

It might also be fun to try to make the graphics appear to not be tile based but
actually keep them tile based. Change the shader (or the game logic) to add edge
tiles. Add something to the shader to offset moving characters over time. etc...

Add more rules, entities: The number one reason I wrote this was I thought it might
be fun to make more types of things. Random simple ideas:

To be honest I think an actual shipping game would be best with a few core features
and then iterating on puzzles using those limited features. Otherwise the player
isn't given a change to master each feature. Still, experimenting could help find
the most interesting features and then you could choose the top 6-10 and build levels
from those

PRs and ideas welcome.

Legal

I have no idea what the legal implications are. AFAICT, Game Mechanics can not be
copyrighted
but of course I am not a lawyer. Further, the game is 38yrs old so there are certainly
no valid patents. And of course, this is just derived. No idea how the original game
runs. In any case though, use at your own risk.

LICENSE

The game is MIT, the levels are licensed by their respective creators. The license
and the creator detailed in the level file itself. If there is no license in the level
file then they are CC-BY.

To be clear, you have my permission to publish a commercial game based on this code but make sure
to provide attribution as required and make sure
you only include levels that have a compatible license. (CC-BY, CC-BY-ND, CC0)

Also, I'd love to know about it!

greggman/rockfall