Although this game isn't terrible by all means, it is too easy and apparently boring. The bosses are randomized, but the random features each boss receives are rather bland, and does little to transform how each level plays. None of the enemies really stuck out as unique, they all have a saucer-shape that makes them look too similar visually.
The controlling of the player isn't fun, he goes far to slow for my liking. A boss would be charging towards me, but there would be nothing I could do because of the lackluster speed of the protagonist. The gun also shoots at a very slow pace, although upgrades allow you to change that slightly.
Each level is pretty much the same every time. The bosses are generally the same, and upgrading the player's weapon only barely alters the game play. These are some contributing factors to why I don't really enjoy this game.
I could however control the player easily, and I can't recall any technical issues. You have real potential to create a great game, but this is not a good example of that.