Hey congratulation for publishing a game
I played it for about 4-5 runs and I always died within the first two rooms. My main pain point was that the gun is really slow and it takes a lot of time to kill enemies, this in addition to the enemies bullets makes it really hard to play. At least for me.
Also I think you generated the Thumbnail of your Game with AI, the pixelart looks way different than the pixelart of your game. This is usually not a good thing.
Just as a tipp in order to generate Thumbnails wich do show how your game looks you can just reuse assets of your game in the Thumbnail and arrange them on top of a screenshot of your Game. Maybe also add a Title on top of it ;-).
Over all a nice first project.