Thanks for the honest review! Honestly, getting a player invested enough to try and push for a high score is the biggest compliment you can get in this genre.
That FPS drop after some time is tragic though. killing a big waves should give you a dopamine hit, not a PowerPoint presentation! It sounds like the browser choked trying to spawn way too many nodes of enemies and drops at the exact same frame playing a native version should help. Doing a proper object-pooling pass is at the very top of my post-jam fix list. Thanks for pushing the game to its breaking point!