This game really reminded me of the flash era, where games were very simple but also had a lot of replayability. What made it very replayable was the upgrade feature, which lets me buy different weapon types and armor which I can use in subsequent runs (my fave weapon btw is the shotgun, it's so good).
I do think however that the color of the background and the objects on the screen can be adjusted a bit, as at times the objects can blend in and become hard to see because of the background. Overall though, I still enjoyed the game, and I am glad I was able to get a high score of 2,913 on it!