I didn't have the issue with the crash, although I stopped at level 44 (at this point I just run forward and SMASH everything in my path ahah). Lovely game, really fun/satisfying and the artwork is the best I've seen so far, awesome job!
Wow!! 44!!! I've implemented difficulty curve but didn't had Time to try It at level 20 and above. gg! I will probably try to modify difficulty later