Add a speedrun timer to this immediately! I would be hooked for a good 30+ mins. The movement is really good and portal placement feels (mostly) intuitive. Refine the whole thing a bit, add some variety and other features, and I think it could feel like a neon white-like game. I would absolutely play a more fleshed out version of this!
I'm not sure if something was configured wrong on my end, but there wasn't any sound - just any basic sounds would improve this game a lot. Also, fixing up wall friction and movement on moving platforms would be great. The portals can be easily exploited to get out of bounds, and when you place them on top of eachother you get a funky visual. Some things to improve / leave in for fun!
As for doors... uh... portal's are definitely just really cool doors, so I approve. Nice and fun experience overall.