Hey man, thanks for the feedback!
Yeah, the breakable environment is one of the things that come up quite a lot, just not implemented yet :)
The skills are used by RMB, the 1-4 is just for choosing the one that you want to use, like weapons in FPS :)
You can see the key binding in pause menu.
The maps are procedurally generated, but there will be more variants in the future.
Cheers!