If the keyboard does not work, move the mouse cursor around the screen. It should take the focus and thus make the keyboard work, although you might need to move the cursor outside the game canvas.

Arrow keys or left analogue stick or dpad: Move and climb
Z or (A) : Jump.
Jump button on air: If you have a rocket pack, you can press the jump button again on air to use “fly”.
Down + jump button: slide. A jar of lubricant is required.
X or (X): Shoot (requires a hand cannon).
Hold shoot button and release: Shoots a bigger, stronger bullet. Requires an improved hand cannon
Shift or (Back): Open a map, if you have one.
Enter or (Start): Open the pause menu. If you get stuck, you can find “Respawn” option there.