Pretty good
Bosses are a bit too easy and redundant but pretty fun otherwise. Also maybe take another look at the hit box for the fireball projectiles? I'll try to help identify some bugs:
Medals:
I guess you already know that the 10th kill and 4th boss medal are bugged, but seems like the 100 achievement medal is also bugged. Haven't had a problem with all the others.
in-game:
-A check mark exists next to the "no bow game completion" achievement even when you have not done it yet, though the check mark looks slightly different from the others.
-In survival mode, ice/fire arrows are reversed when dropped from monsters.
-When you quit game, the game repeats the armor games logo (have to refresh to play again)
-When you go to options and set ti low quality, the game still runs at medium quality when you start. I was also able to right-click and set quality to low manually in later levels. The play, stop, pause options also came up. Perhaps you add some buttons to adjust quality while playing.
I also recommend proof-reading all of the achievement descriptions :P
Overall very good. It's also good to see an author replying to comments :)