Overview
Index users will notice they get no in-game map of Knuckles controls. Here they are for ya.
Menu
First off, you’ve probably loaded up the game up and noticed that the A and B buttons do not advance anything in the menu. Instead, press and release the left touchpad with your thumb while an option is selected (by you looking at it). You could also use the left stick because this game interprets each pair of sticks and pads as if they were 1 input per hand.
In-game, forget about A and treat the B’s as if they were Start and Select; they perform meta functions.
Left B pauses the game. You can exit the pause menu immediately by pressing any input other than left touchpad/stick.
Right B re-orients the game in the direction you are facing. Probably only useful during seated play, and can also make you dizzy if used excessively.
Left Controller
Moving the left stick or touching the left touchpad will poke things.
Holding the left trigger down and turning your head will sling objects around. This is pretty finicky and I could not find a control to move things closer or farther from yourself independently (so please comment if there is a way to do this). While using Telekinesis you can poke objects to turn them around, as well as use your other psypowers.
Squeezing the left grip will burn things.
Right Controller
Releasing the right touchpad or moving the right stick will shift Raz’s consciousness into any viable living creature’s brain. This is your movement key in this game.
Pulling the right trigger will shoot things. Like a gun. Pew pew!