For what's available it's not bad, but it has it's edges. For starters a bug I encountered was that trying to do the 3rd stage for ironically a 3rd time cause no enemies to spawn so I just stood there for a couple of minutes wondering if I just didn't see things.
Other than that it's clear the game is going for the reverse bullet hell/bullet heaven style and in that regards it does have things that make it different compared to others. For starters just the fact that is has different missions instead of just the same survive till the end and fight a big boss, but it also has no progression. Sure, the enemy switch up in Episode 3 was nice, but the second mission being 5 minutes long fighting the same charging cultist guys grew very old 2 minutes into it.
I would suggest the golden cultist guy be changed into something that makes him stand out, Maybe make them target the player or be immune to the monster requiring the player to do it themselves, so you can't just stand on top and do nothing other than occasionally leaving.
Also cut the time in half.
other than that maybe give the player the option to get a different weapon, only in the next episode I mean. The first 3 with the knife is fine, but any further less like a bullet heaven and more like an incredibly strange top town stabbing simulator.
I am curious to see where this goes.