Delver [Steam, Official Site] is a positively rated single-player first-person dungeon crawler, which has just today left Early Access. It has also seen the return of the SteamOS icon for it.

I actually spoke to the developer on Twitter to query what was happening with the Linux version, since it did support Linux it just didn't have a SteamOS icon. It's actually one of the games Valve removed the icon from some time ago, when they noticed a few games not launching correctly on SteamOS directly (even if it was fine on a "normal" Linux distribution).

The developer wasn't sure about shipping a JRE build with the game, so I quoted their tweet to get them a little exposure and a bunch of people offered their help. It seems the developer figured it out, so it now properly advertises Linux support once again with the SteamOS icon for the full release today—awesome!

Game Features:

A silky smooth mix of 90s FPS combat with classic RPG mechanics.

In these dungeons once you're dead you stay dead. Permadeath means that when you die, you begin each run into the dungeon anew.

Tough as nails gameplay will test your skills, no grinding will save you here.

A procedural dungeon that will keep you on your toes, no two runs will ever be the same.

Delicious chunky pixels!

You can find Delver on Steam or directly from their official site.