That's a really solid game with amazing art! FYI: I got soft-locked on the 2nd level - all my minions froze, the waves stopped and the remaining counter was at -1 so I had to reset
I think it was around wave 5ish? I was down to very few enemies before it happened. You may just need to check if remaining is <= 0 just in case it goes under 0 somehow. I'm afraid I can't give much more info than that.. It was kinda random