as a massive tetris addict and moderate idle game enjoyer, this is/was a very fun game, however it can be unfriendly to beginners, so the difficulty curve could be adjusted a little.
the game starts very slowly, but as soon as you get the last ai level, it starts to be surprisingly fast, idk if this is by design but it seems a little weird.
overall the game is good, there could be another prestige layer for more overpowered things (e.g. +1 mino per drop) and something so active play is more rewarded.
good job/10
ps: a solution for the lag issue can be to just place it instantly at small intervals, not bothering with gravity and stuff