Well, the movement in this game is some sort of hell... I liked the scale portal concept, but the simple attempt to go where I wanted was an ordeal. Less drifting, and a camera you can control on the y axis too would change A LOT the experience. And I could not interact with the yellow cube by pressing or holding E; when I tried to make it pass the portal (and boy was it difficult to push it in the direction intended!), it just got stuck inside the portal, preventing me to go back in the mini scale zone.
I want to see what puzzles you can do with those portals!