This was quite fun too play! Spinning your huge sword super fast in circles like a maniac was very enjoyable, and the upgrades were quite nice. It is sad that there is not really an ending, after round 10 the enemies stop appearing.
Thanks! In all my testing, I never made it past level 8 or so, so given my time constraint I thought 10 was safe enough. Honestly, I'm pretty sure the game should actually just crash past level 10 (index outof bounds error), but another commenter seems to have made it all the way to 13 somehow...