Hmmm.....

puyo.fall

blocks = {
 |&*,
}

colors = {red, green, blue, yellow, white}

discrete

stick immediately

collapse

tetris.fall

blocks = {
 |$$$$,
 |**
 |**,
 |##
 | ##,
 | &&
 |&&,
 |===
 |=,
 |~~~
 |  ~,
 |%%%
 | %,
}

continuous

stick after 1t

float

on stick {
 clear horizontal full
}

arena = 10x20

I'd be sure to include something about it being 10 width, 20 height. You may want to include it getting faster over time, perhaps.

Puyo Pop's rules are 6 wide, 12 tall, and blocks collapse instead of floating. 4 or more of the same color breaks, and after every break (or rather, after every everything) blocks fall, and if four or more of the same color are touching again, they all collapse again.

Puyo has between 4 and 5 colors (depending on your difficulty mode) and nuisance blocks.

There's also nuisance blocks that break if blocks break adjacent to them, but don't break if four or more of the same color (gray) are touching them.

Also, there are steel and "block" blocks that don't break under any circumstances, and the block ones don't fall at all.

Puyos in old game modes always fall in sets of two, but in later game modes fall in sets of two, three, and four. The pairs being randomly likely to be any two colors, including pairs of the same color. The threes are always a pair of the same color and a third block that is a different color. The fours come in two varieties. A pair of pairs, (two of each color, and always two different colors) or if you're lucky, four of the same color and if you rotate this block, it gives you a different color. So four reds, and then if you press the rotate, you get four greens, four blues, four yellows, etc.

Doctor Mario uses 8 wide, 16 tall, and has two kinds of blocks. Virus and Pills. Pills always fall in sets of two.

Viruses float, pills fall. You will never get a virus through the rotation of falling blocks.

If four or more of the same color are touching in a row or column, and one or more of those is a pill block (all four can be pills but all four can't be viruses) then they disappear.

Pills fall in pairs. Pairs remain connected to each other until one half of them is destroyed. When that block is destroyed the other half of the pill will fall straight down until it hits another block of some sort, or the bottom of the screen.

A level is won when all of the viruses are destroyed.