Love the visual design on this, especially the mech! It looks fantastic

The platforming got a little finicky at times, which killed me a couple times. I was a little annoyed that falling was just an immediate game over instead of a health cost or some kind of checkpoint, but it's both period-appropriate and not a big issue when the overall length isn't enough to make repeating the first sections feel like a chore.

Like some others have noted, the projectiles don't really move in the way I have come to expect, and tend to veer off in some unusual ways. The movement is also kind of slidey - if you stop after walking or running, the mech slips forwards quite a ways, and I think that ends up making it difficult to position precisely to aim at and hit a lot of the enemies. I think this ended up combining with the big health pool to make me eventually just kind of crash through the game as quickly as possible while shooting fairly little until the boss.

While I do like the jets, I think having some snappier movement options might be nice - I saw in another comment you mentioned that the boss's slap is kind of unavoidable, and I think that's both because of the animation and because of the movement speed being lower. It might be cool just to have the jet button make you do a jump if you use it on the ground - that way you can get higher faster, but you still get to make use of the cool platforming that's already there using the jets to dip below obstacles and stuff like that!

Beautiful, I love the art. The slime animations are particularly juicy! I found some of the platforming to be finicky, although it got much easier when I realized that I was far too afraid of the slimes. Once I became OK with taking on a few slimes here and there, the game got much easier. It was very satisfying to get past the pipe platforming section. The boss fight went pretty quick once I got there on my 5th playthrough :)