i really like the puzzles! they got my brain braining, maybe a little too much tho, so a slight difficulty nerf could be pretty handy. other than that i really do suggest adding in some more audio cues like when a button is pressed, when a box falls into a hole, etc. a bit more visual feedback could also be handy like the doors having a dust particle effect and being brighter when opened (darker otherwise), and maybe adding a ui element with K(blue)+L(red) with the use similar to the crosshair in Portal, then make the portal doors entirely orange and blue instead of just having outlines of those colors. regardless, great game!