[aardvark179]

Hmm, combining blocks by sliding in below the top a stack can leave the top of the stack floating in space when the new combined block merges with the block below it, and this feels weird. Then if you combine something with that floating block it will fall, closing up the gap and then potentially combine with the block it landed on.

[mistercow]

A similar weirdness is that it doesn't feel like it should be possible to ever have two of the same number stacked vertically. Feels like the rule should be essentially that "down" is pressed at the end of every turn until it stops compacting.

[prat0318]

Yeah, i noticed that as well while testing. Fixed it now.