doodle/dev-assets/doodads/regions/fire.js

// Goal Region.
function main() {
    Self.Hide();

    Events.OnCollide((e) => {
        if (!e.Settled) {
            return;
        }

        // Only care if it's the player.
        if (!e.Actor.IsPlayer()) {
            return;
        }

        if (e.InHitbox) {
            FailLevel("You have died!");
        }
    });
}