Maybe make the down arrow key for sliding also.
the game is ok,just boring.
The portal shots control like a paper airplane mid flight.
While the game is boring as its doesn't has much to offer,it's still good.
However...maybe make ENTER or the SPACE BAR to enter the portals.
Also,i had to GUESS how to use the portal gun,i mean,YOU SHOULDN'T GUESS HOW TO USE AN IMPORTANT GAME MECHANIC.
maybe add more puzzle mechanics.
also,maybe check some other games,it could make you think of something to use in your game.
for example,In portal 2,you use gels to make portal surfaces,jump higher and speed up in the game.
They actually got that idea from a game in steam where you can paint the walls and ground so you can jump,run or stick to walls and poles that you can't stand on.
Overall,the game is ok,it has potential for it being a beta.
It just needs something to spice it up a little,like an end goal,even if the story is very simple, and some refining