I really enjoyed the visuals of this game. Drawing all the different sizes of objects by hand and not letting the engine do the scaling itself was a great bit of polish that I appreciated.
The way the game explores it's mechanics is very thorough. When I first saw the mirror, I thought "I hope you can scale yourself with those at some point too" and the game followed through, which made me real happy!
I feel you struck a nice balance between all of the different scales and their pros/cons. Many of the "scale objects" type games in this jam I feel fall in this pit where the middle sizing doesn't really serve a distinct purpose, however in Port-a-Scale, I felt the middle size served a rather distinct role.
I enjoyed that you changed the way items behave on a far more interesting way than most (the way that ballista bolts start dropping down if they are big was great).
My only criticism is that the ray gun bullet was really small which made timing some of the shots a bit more difficult than I feel a puzzle game such as this needed. Of course you could lean into it and make the ray-gun more of a platforming tool, but even then I feel the bullet itself could have a bigger hitbox in relation to the player.
All in all, great work! Definitely one of the highlights of the games that interpret the theme as "making objects big and small".
PS: I encounter a bug where a box fell on my head and caused me to clip through the floor. Nothing too bad, considering you can restart the level, but still wanted to fill you in.