Thanks for playing!
The UX for weapon switching is on me, it was supposed to let player select with the secondary directional input(Arrow keys or Right analog), but I haven't figure out a good UI design to indicate that.
For the crash, I guess it was probably caused by the massive amounts of coin spawning when a character is destroyed by the monster.
"I enjoyed shooting money like a rich hahaha :3" Glad you enjoyed that XD