Yeah! I feel that potentially a few balancing tweaks could help in this case.
I know it’s a lot to ask, but could anyone do a screen record of one of these really long playthroughs of the minigame? I just want to see what is going on when this happens. And I will try to fix it, as going on for 20-30 mins is crazy……
Unfortunately, I believe it's simply not possible to recreate these long games authentically once you've gotten the hang of it. But I'll try to recall my first attempt from about a week ago as accurately as possible:
1. Started off playing just as regular tetris, filled up around 15 rows without any gaps whatsoever.
2. Pressed shift, see a bar filling up and figure that I have to wait for it to fill and then everything will be cleared.
3. Confusion quickly turns to panic as I try to move the next piece, only to find I can't and at one point the bar suddenly dissapears, with only one row cleared.
4. Try experimenting with pressing shift when the bar reaches full, figuring that might do it.
5. Notice the button to the right of the arrow keys and discover pressing it while in drain mode clears a row.
6. Use this to clear most of the board and gain myself some time to think, by this point several gaps have appeared.
7. Play for a while continuing to experiment, finally work out the system after around 10 minutes but all the time spent looking away from the tetris part and experimenting has left me with over half of the board unusable.
8. Play relatively conservatively to minimise the risk of losing for the next 20 minutes, clearing only 1-4 rows at a time, and sometimes without any regard for timing bonuses.
If you only clear a couple of rows without timing bonuses you get maybe 6 mL, but if you're close to a full grid that's all you can safely do. The game is still very manageable at this point, I never really felt at risk of losing, but getting to 1150+ mL like that is painstakingly slow.