Controls: Arrows/D-pad: Move & Jump. Blue btn (Q) = place blue portal. Orange btn (E) = place orange portal. Aim with cursor/touch. F = grab/drop cube.
Portals: Place on white portal-able surfaces. Black grid surfaces reject portals. Enter blue portal -> exit orange, preserving momentum!
Momentum puzzles: Fall into a floor portal, launch out of a wall portal to reach high areas.
Turrets: Stationary guns fire at you. Use portals to flank them, or drop the companion cube through portals onto them!
Companion Cube: Carry it (F key) and place on buttons to weigh them down. Essential for puzzles.
10 Test Chambers of increasing complexity. Fewer portals = higher efficiency bonus.
Score: Chambers completed x portal efficiency percentage.
Keyboard: Arrows=Move/Jump, Q=Blue Portal, E=Orange Portal, F=Grab Cube