Good work!
This game is full of juice, so you can start from here to build something bigger and deeper, I love how you managed your sound effects, particles and visuals for a really tasty gamefeel. Your character is super cute and the mech improves the experience a lot.
I don't know if I didn't go too far, but I didn't found some kind of threat that could justify using of a gun.
You can expand this idea and find more mechanics to merge with what you have done to create a really cool and immersive experience. Don't forget to always surprise the players. Great job!