Welcome to the forums!
I tried your level, it does remind me a lot of portal, but it kinda stops before anything deeply interesting happens! It seems pretty good so far, my only complaint is the heavy use of signs instead of sign areas. Sign areas are used to trigger the showing of the sign, so that it doesn't move. Signs make the message appear where the sign is, but sign areas make it appear at the sign- but for more than one location. For example, right now you have a bunch of 'Sign A' on each screen, instead replace all but one of them with a "Sign Area A"... -you'll see what I'm getting at once you test it in-game. (Sign areas are objects 29-31 in the system bank). Just try messing around with the sign areas; you'll see that it's a lot better.
I look forward to seeing how it goes! Good luck