Thank you very much! Indeed, the boss is the roughest part of the game 'cause it was one of the last things we did, though we're planing to launch an update that fixes him, sorry about that T_T
The "Space + K" crash tends to happen because of an error trying to recompile the shaders in the engine we use, just out of curiosity, do you have your graphic card's drivers up to date? It's a crash that tends to happen because of older drivers!
Thanks for the feedback, we appreciate it! ^^