..., as well as an API gateway REST endpoint backed up AWS Lambda handlers to start a game and view game connection information. The Lambda handler always returns a 501 Error (Unimplemented). Single-Region Fleet, this scenario creates a game backend service with a single GameLift fleet. After player authenticates and starts a game (with a POST request to /start_game), a AWS Lambda handler searches for an existing viable game session with an open player slot on the fleet.