BUDDY & COOP MECHANICS
Press [Right Stick] up or [Shift] to call Buddy in single player mode.
On CoOp, you can assign the camera to Buddy by pressing [Right Stick] up.
Hold the Jump button [A] to scan objects and wall structures. This will give you clues about how to interact with objects and which walls are breakable.
Hover over an object and press the Steam button [RB] to lock it. Use the Fire button [X] to apply telekinesis. Implemented for build 1.45 Buddy will now pull only.
To rotate an object, press the Jump button [A]. For build 1.47, the rotation controls were also simplified. The object will now always rotate clockwise.
Upgrade your hacking level by collecting Corridium protocols. Build 1.51 (Dec 2019) simplified the game's hacking mechanics.
Scan an enemy to determine its hacking level and the effect hacking will have on an enemy.
Hold the Fire button [X] to load a hacking protocol and release it to fire the hacking seed.
CO-OP SPECIFIC MECHANICS
CoOp mode exclusively allows Buddy to create blocks by pressing [RB] and alter the game's level design.
Buddy's slingshot-like hacking seeds will also inflict damage on non-hackable enemies, enabling Buddy to actively engage in combat situations. Also, many bosses will expose a CoOp specific weak point.
Those CoOp specific mechanics will fundamentally change the game's balance and feel, allowing for CoOp speedruns as a very unique take on the Metroidvania scene. Bock building is not allowed in certain key rooms though, where Buddy's blocks will be destroyed by guarding turrets.