You should really give some enemies some more hp and movement speed, also
add healing items randomly spawning on the map, that would be a great reason to actually walk around
also you shouldnt really use a timer just to kinda force people to play for a certain amount of time, just do a wave system that you can scale up infinitely so they will get to something hard for them to beat at about the same time as other people
the concept is okay, but the repetitive music and the slow pace of everything really numbs the experience (if you compare to something like vampire survivors)
if you had a hard time making music just pick a simple royalty free track from youtube or use AI if you dont mind that kind of stuff, at least AI's is somewhat decent enough to make a music for these games (i recommend Suno)
This concept has potential but we need to make it feel less boring to play, no offense