Menu UI: A/W or Arrow Keys to move, space to select. Click or touch UI on mobile
Keyboard: Move with Arrow Keys or A D | Jump: Spacebar or Up Arrow or Z or W | Y to restart at last checkpoint | ESC for Menu
Controller: Joystick to move | A to jump | Y to restart at last checkpoint | Start for menu
Mobile: Move with touch buttons on the left side of screen | Jump with touch button on right | Tap the top of the screen for the main menu

Game is choppy/low FPS: Toggle the PERFORMANCE button in options for smoother gameplay. (Defaulted On for mobile)
Too zoomed out: Toggle the ZOOM button in options for a zoomed in view on the player. (Defaulted On for mobile)
Can't start: Highlight the start button with A/D and press space (Keyboard) or Joystick and A button (Controller) or click Start. On mobile just touch the start button