First of all, the presentation is immaculate. Amazing job on that! I love the creatures, the music is very catchy, and the pixel art is great.
The gameplay is really good, the platforming is rock solid, but suffers from a few flaws here and there. The biggest of which being unclear hitboxes (i try to crouch bullets but they still hit me?) and not being able to see faster enemies as they approach you from offscreen. Furthermore, the boomerang weapon is a bit complicated to hit enemies with - I found myself using the creature catcher bottle on enemies I had already captured just because it travels in a straight line.
Overall an amazing job!