Hi there, that would be a nice addition. Not easily doable I'm afraid
Viewing post in Cosmic Collapse, a suika-like comments
Ahh, a shame! We usually play Suika-game on Switch in VS mode, along our Tetris-like sessions. A 5-second limit to hold a piece is a gameplay-mechanic, and it has game modes like "Time-Limit" (5 min score attack) and "Attack" (Build up a meter to send your opponent increasingly larger garbage)
Maybe a actual 2-player mode can be done in a sequel in Picotron or something in the future. A Super Puzzle Fighter 2 type of garbage mechanic (countdown for garbage-pieces to be allowed to merge) might work in a Suika-like!