I would rate this game 3.5/5 and i played through stage 1 to 4. I think for positives it's visually very nice with good animations and music. However I think gameplay could be tweaked to be a bit more fun and varied.
Enemies for example are way too similar and just follow you, same with the bosses as well. Not every enemy has to be super unique but just give some enemies/bosses their own special attacks like shooting projectiles or charging at the player. That way theres some variation to how you move on the field rather than just looping around a big horde of enemies for the entire round. Ik vampire survivor games aren't supposed to be too complex but I think this could help with gameplay alot.
Also I dont know why the enemies just cant attack you when a boss spawns in. whether its intentional or not, it makes the boss really easy to fight.
I also got stuck in the first map here and couldnt get out:
And then i actually beat the stage by just staying in this place (why i think enemies not harming you after the boss is a really strange choice).
So overall the game is pretty good just work on varying the gameplay (maybe add some more upgrades as well) and this should be a pretty fun game. Cause i did think the game was a bit easy since i got up to stage 4 with no upgrades only using the base ninja.
Also please check out my game if you have the time thanks.