First of all , good game and congrats on finishing it , I loved the variety of levels and the addition fo something new along the way , the game fits the theme and is kind of different from many other games , gameplay was fun.
You told me you wanted my feedback on the pixel art so here it is :
- the graphics is not bad but it's very simple,
- the style doesn't match since the character has an outline and the tiles and everything else doesn't have an outline so try to keep that in mind next time.
- there are mixels which are different sized pixel which appear when you scale something in the game engine ( unity for example ) and mixels look pretty bad tbh , there are many stuff with mixels like doors and the magnetic field arrows.
- the art doesn't have any shading , it just has pure colors , so for that , you need to consider a light source , consider light is coming from above , so the upper part of the art must be shaded according to that and the lower parts must be darker.
- shading must appear clearly cuz pixel art is mostly based on the contrast and not gradients ,so make the lighter areas lighter and the darker areas darker.