Open Options on the main menu. The same settings are reachable from the pause menu during play.
Game
Choose a language; adjust screen shake, reduced motion, intro video, tutorial hints and what happens when you switch away from the game.
Audio
Set master, music and effects volume separately.
Video
Pick windowed, borderless or fullscreen; adjust VSync, resolution, frame cap, prop shadows and brightness. For brightness, follow the calibration marks on the screen.
Controls
Choose a binding, press the new key, then close Options. Cancel/pause is reserved so you can always leave a menu.
Reset to defaults is at the bottom of Options. It keeps the chosen language. See How to play → Controls for the default inputs.