Graviton is easy to learn and fun to play!
Here's some tips to help you out if you get stuck.
"Why can't I activate the portal?"
Only the top left portal can be activated by pressing F when standing close to it.
"I've located the boss room but why won't it let me enter?"
You need the key. Try looking for this room and pick up the key with F:
Controls:
Move: WASD
Shoot: Left mouse button
Pick up item: F
Switch weapon: X
Drop weapon: E
Abilities: 1 & 2
Player stats window: P
Inventory: I
Pause menu: ESC
Fullscreen map: M
Zoom map: + & -