Hey guys. :) Just thought I would add that Steam Play does not mean Linux support! Also, Botanicula is currently not available on Steam for Linux.
This post from Valve explains what Steam Play is:https://support.steampowered.com/kb_article.php?ref=9439-QHKN-1308
Hmm... I'd quote the post verbatim here, but a couple of sentences are slightly confusing, IMO, so I'll reword it slightly and attempt to clarify things just a little:
Steam Play allows you to purchase your games once and play anywhere. Whether you have purchased your Steam Play-enabled game on your Mac, Windows PC, or Linux PC, you will be able to play it on another platform free of charge if the game has been released on the platform that you are attempting to play on. (You'll need to look for the little Apple, Windows, or SteamOS logo in order to see what platforms a game has been released on.)
Edit: If it's still a little confusing, here is an article I found that goes into a bit more detail and has some images:https://www.gamingonlinux.com/articles/how-to-tell-what-steam-games-work-on-linux-steamos.7009