A few ideas to improve the gameplay from my perspective:

1: Put some bounds for the camera, so it doesn't follow the player 100%, but lets you run around the middle without moving the camera.
2: Make the enemies circular, so the hitboxes are more predictable

Otherwise, fun little game! My high score ended up being 100 points.

A very challenging game, but it works well and you can quickly go again, so it's addictive, you feel very cool when you destroy a merged enemy :D Good job, had fun playing it!

Soooo hard ! ^^ Best score so far : 21.
The idea is very simple but it works. good job !