Great job on this Peter! Puzzles are well conveyed, they can be tricky, but never unfair. You've done a real good job with the portals, very easy to understand. I Love the small details like blocks rocking after falling from a high place, that's the sort of stuff I really like. Carrying/stacking of the boxes feels pretty solid. I might suggest working on the gravity/physics of the player a little bit, I feel Porter is a little on the floaty side, but that's more personal preference.
I found a few little things that have already been mentioned and one big thing that will need to be looked at. You left the debug buttons in by the looks (R = restart). You can hold a block, jump, drop then walk into the block and it seems to reset your jump, meaning you can jump in midair. EDIT: You can jump, press B then jump straight after, you'd don't need the block.
Other than that, you've got a really cool little game here, great job!
Thank you so much for taking the time and giving feedback, I appreciate it.
Details are hard to find time to add in a jam, but I agree, the polish is what I really enjoy adding. Would love to have had time for more.
Agree about the floatiness of Porter. After the jam I'll change it a bit. I had left it like that so he gets knocked more when a moving box hits him, but I'll adjust it and only let it be like that when that occurs.
As for the jump bug, that's a nice find. Something I hadn't actually tried. Was a state change problem, and have fixed it now so will update post jam. Great feedback mate, you obviously tested all the systems for problems, so appreciate the thoroughness.
Once again, thanks for your time. Good luck on Flynn, I love so much about it, and talking of polish, Flynn just has it in spades. I've played the demo, so can't wait to play the full when it's released.