Halcyon implements the official v83 key-config system — every action below is remappable in-game (open Key Config with \). These are the defaults.
Click the game window first to give it keyboard focus. The offline engine sandbox handles the client-local actions — walk, jump, climb, portals, attack, sit and emotes — while skills, items, menus and anything with another player or monster need a live server. On touch devices an on-screen D-pad and skill bar appear automatically.