Solid autoshooter, pretty good pixel art. Could use some more originality, clearly copies a lot from Vampire Survivors. Using another game as a basis is normal, but don't just copy half of the weapons from that game. It makes it very bland, feels like I'm playing something I already figured out which is boring. Like others I had the invulnerability bug. After one hit my character stayed red and didn't take damage.
Keep it up. Be bold and don't give up! People love new mechanics. You can use existing stuff but make sure to mix it up a bit more! Think about the basic mechanics in your game, the very basics, and how they could be different compared to your inspiration. What's the attack like? Do the enemies work differently? Maybe have them spawn in another way or add special movement patterns. Make a list of everything the game does and try to change as much as possible.