New update
About it; 
Let's be honest here, collision detections were a bit janky at best, game breaking at worst. That came down to the fact that I was letting unity decide most of the things happening and didn't have time nor thought process to figure it out myself.

So now that I sat down and thought it through, I've updated the game with more responsive collision with the player but that's not all, I've also adjusted the management of tetrominoes so they aren't in conflict with each other as much as before while in the air. Basically what I was doing wrong is, again, let Unity decide even though I already had the mechanism to make them work properly.

Misc.;

- added score indicator about time left on level ending
- added height indicator on HUD and in the background; those in game indicator remove the confusion when standing on things going down. Yeah, that thing when you think things are static while in fact they're moving down but you have no way to notice it;