Great feeling and a lot seems to head in the good direction, including sound design. I would recommend having better highlight or differentiation for some sprites/scenery. Like the blue slimes I found a bit dull in terms of "shininess", or the green crates being too discreet. The weapons factory level had some passages where the practicable terrain was not instantly seen for me, playing with contrast would help.
Overall I enjoyed the playthrough. It's simple but it feels good and flows pretty well.