Thanks for the feedback!
The hard drop and reverse rotate are specific for the ninja character. Once I finally make a proper controls page that can be customized I will explain it better there.
There is a character that can't see any blocks and there is also a curse that prevents you from seeing them. Maybe that's what happened to you?
That's a good idea, I will try to make it more flashy. Combos will be added as an upgrade probably but if it's too interesting it could become a regular mechanic.
There are blocks that crumble and disappear and blocks that become invisible but are still there. Maybe I should explain it better in the tooltip