Trivial
Contains none of the elements listed for harder levels.
Easy - one or more of:
Requires changing the axis of momentum ("flinging").
Requires placing portal endpoints where both cannot be seen at once.
Requires completing a series of actions within a time limit.
Contains hazards that can kill the player.
Standard - one or more of:
Requires placing a portal while flying through the air.
Requires sending a single projectile through multiple portals.
Requires carrying a specific object through all or most of a test.
Requires completing a series of actions within a time limit to avoid death.
Advanced - one or more of:
Requires placing two portals while flying through the air.
Requires three consecutive momentum flings without stopping.
Requires placing a portal while standing in a portal ("tunneling").
Contains gun turrets that cannot be picked up or knocked over.
Super-advanced - one or more of:
Requires placing two portals each during two consecutive momentum flings without stopping.
Requires redirecting more than one projectile in flight at the same time.
Requires traveling through a portal while also redirecting a projectile.
Requires a player or projectile to enter the portal surface obliquely.
Requires causing a turret to disable another turret.
Requires creating a positive momentum-gathering feedback loop.
Requires accounting for the travel time of the portal projectile.
Murderous
Requires performing a super-advanced maneuver within a time limit to avoid death.
Impossible - one or more of:
Requires use of a glitch such as wall-climbing.
Cannot be completed.
