The opening artwork captivated me instantly. The cute pixel sprites was nice and you have made a great tutorial level! The fights wasn't overly difficult, but I somehow kept getting hit twice before the boss fight, making it a stressful fight.
The chain reactions was masterfully implemented! Tying it to the shotgun reloads, as it is such a strong weapon, was genius. It made it so that during the the final boss fight, I was able to expend both shots and get the reload off the small Egg goons. A good cycle.
The enemies having the same speed as the player made it hard to outrun them, which is more of a player issue as I had to focus on the closest ones if I didn't already get them in a chain reaction.
Great job on the game!