I've completed the game, and bought all upgrades, but i found a bug... If u buy items in easy mode (cheaper upgs), u can toggle it to hard mode, and then refound the upgrades for a higher value
Good find! I know about this problem and actually manually made it harder to execute by updating the prices only when skill tree is opened anew. I decided to leave it in because it was not worth the time it would require for me to fix it considering the jams duration. Only smallest percentage of the players would ever find out about it haha. Cheers.