Drag portals wherever you want. Click to change axis. By the way, speed will cap out at one point and make you go slow again. The website does this to prevent lag, and/or the website breaking.
Update Log Ver 1.1 Portals can rotate Ver 1.2 Made portals look better. Ver 1.3 Added background Ver 1.4 Found out I messed up with the background in the last update and ruined the floor because it is entirely color based, then fixed the issue Ver 1.5 Added new wall texture for realism.