I was about to buy this game (for once this is something I would get on itch and actually pay money for it not just giveaways), since this is actually a game I could like. But since this only give you a steam key I will not.
Not sure if this game use any kind of drm on steam (there are a few drm-free games on steam) but I prefer to get an installer instead of using a client for the download even if the game itself is drm-free on steam.