Thank you for the detailed feedback.
The UI part is funny, because I totally agree with you. Basically I just put it together in the game's early stages and in the end haven't changed it. The funny part, that so far everyone loved it, many specifically mentioned the UI. But I hate it :D I should have changed its style mid-way.
The random hits thing is concerning, because I never saw this happen. I don't know if it is a Linux specific thing, sadly I cannot test it. On Windows, Mac, Web it is not a known issue. As for NOT taking damage, there is a timer in the game that doesn't let the player take damage from multiple sources in a quick succession. This is by choice, because the geometry of the map is quite "detailed". So there were cases, where you got slammed into a wall, and took damage from multiple protruding edges.
All in all thanks for the feedback and for playing the game. Cheers!