Aesthetics is incredible, you nailed the presentation with the retro vibe! Character changing shapes and weird looking creatures adds a lot to this. The metaprogression with the upgrades and saving the enemy count was also an interesting idea.
Though I wish you put more effort into the enemy design, since every enemy in this game can be safely killed by shooting the laser gun outside their range. I think there should be extra enemies to counter the ranged weapons, so the left-right hand system could achieve its full potential.