One of the most unique and fun puzzle games of the bunch. I completed it way faster than I anticipated, but for a casual player the playtime is pretty fine. I love the concept for the portal gun and how the game invites you to play around with it to try and get different outcomes based on object positioning and momentum, I really dig it. Also the atmosphere of the game is phenomenally executed, it starts like a normal series of tests, but you slowly start to realize something is wrong to then start digging deeper within the facility, it's fascinating. Also also, GlaDOS is an amazing antagonist so far, hands down.
I can't wait to play Portal 2 now, I know it's gonna be even better!

PS: I'm so sorry, Companion Cube :(