We made this  demo in 8 weeks as a proof of concept as part of a University assignment. Our goal is to turn this into a fullfletched published game. Would this be something you want to see fleshed out?

We are dying to hear what you think?

Awesome proof of concept. My one gripe is that you have to be right next to the portal to interact with it, which, unless you use this as a layer of puzzling for your levels (maybe some portal frames have a timer where the portal will close after "x" amount of time so the distance you can interact with portals restricts which you can use), is really just an annoying aspect. As development furthers and you get a fully fledged game I would suggest coming up with more mechanics/ interact-able items such as the launchers and switches in Portal.  In addition you should offer red hearings such as portals that are accessible but useless for the solution of the puzzle, in order to increase difficulty. This is all assuming you are going for a puzzling heavy game, however if you are going for more of an artistic, adventure, or narrative game i would suggest in addition to either a story or a narrative theme (etc) adding some simple platforming and increasing the jump height of the character, just to add some more exploration to the game.