Fr0z3n

At about the 1 minute mark, you have to shoot a portal through a bunch of foliage to get into the next little area. I don't think that panel is highlighted well enough for players to get the subtle hint to use it to get up there. Ontop of that, it's not really common for players to be able to shoot and walk above a drop-tile ceiling like that in portal 2, so you might want to highlight it a bit more. (That all being said, I really love that idea) At about the 2:30 mark, you shoot through the hole in the window towards the opposite wall. That looks like a pretty tight shot. Maybe consider opening up the shot a little bit to allow for wiggle room for players? Also, as someone said making the time travel bits a little bit more interesting visually would be really cool.