This game is extreme fun. I like it, that the enemies can pickup powerups too. More weapons (Especially something automatic or able to pierce through enemies) and enemies would be cool. I like the fact, that it is sometimes like "risk for reward" for the powerups, because it is often surrounded by enemies. It is also very cool, that  the music changes if you pick up the speed powerup. Now i want to talk about the downsides of this game. Sometimes enemies are spawning nearly inside of you or like 2mm away, so u lose a life if you slightly move. Like I said, more weapons would be cool, because the finger gets exhausted due to clicking. The sprites for the powerups doesnt fit very well to the artstyle of the player and enemies in my opinion. Pixel art only fits with pixel art, and not with high resolution sprites (In my opinion). The music sound like a pixel-rpg bossfight, but it kinda fits with the energetic gameplay. It seems to me, that the game doesn't really have its own twist that makes a game unique. For the twist you could implement a special feature. For example: The speed of the game depends on how many CPS (clicks per second) you have. If you have 2 CPS, so the gameplay will be slow and if you have 4, the gameplay will be faster. My example is just an example and doesn't have to fit in your game. If you want, you can use my example and try to make something fun with it. In conclusion this game is good and very fun, but needs more cool features (especially a twist) and bug fixes and an art style that fits. Don't give up and keep making games :).