The Patreon is for their "Studio" not individual games, so if you pay for it you are paying for all the games they make.
The steam price is a single purchase of a single game, Patreon is continuing payments to get all the games and all the updates, If you stop paying you lose access to the downloads.
The steam price is a single purchase of a single game, Patreon is continuing payments to get all the games and all the updates, If you stop paying you lose access to the downloads.