Therefore Games have announced that their popular roguelite puzzler DemonCrawl is coming to Linux, and it's currently in Beta with a release due in a few weeks. I've not played this one myself yet but it does look quite fun. The basic idea of Minesweeper, with roguelite and RPG mechanics thrown in with hundreds of unique items, stages, and abilities.
There's an absolutely huge amount of content included with 600+ unique items, multiple difficulty modes, 50+ different stages to battle through, special 'stage mods' to dramatically change how you play it, multiple game modes and open-ended progression allowing you to find and spend tokens on character Talents. On top of that there's even online leaderboards, Steam Achivements and more.
While playable in the Proton compatibility layer, it does have a number of issues. In the announcement, they said that the problems don't exist in their new upcoming Linux version. They will only officially support the latest stable Ubuntu build, but it should work across most distributions and they shared a shot of them working on it: