Standard chess rules apply, but there is a second way to win: march your own king onto one of the four central squares (d4, d5, e4, e5) and hold it there for one full move.
Rules
Read before you play — no surprises mid-game.
All standard chess rules apply — checkmate still wins normally.
Moving your king onto d4, d5, e4, or e5 wins the game immediately, even without checkmate.
Your king must still only move through legal, non-check squares to get there.