Hey, really nice achievement! Hope you had fun and it didn't start lagging too much once you got this far.
Since this is a jam game (made in 9 days in a work week) there's definitely some balancing left to do and we will probably do one final update after the voting period of the jam is over. Ideally, we would want the difficulty to continue scaling such that it isn't possible to go on forever.
It's definitely not easy to get this far, most people struggle to get past wave 30ish, so again, nice achievement, well done!