Moonsigil Atlas is easily one of the most unique deck-builders around, and the latest major update to the demo has me hooked. You have to try it.
A game we've covered here at GamingOnLinux a few times because it's just so cool. Deck-building where you don't fuss around with an energy system, or limited action points. Instead, you play your cards down in a physical space, with each having their own shape that you need to fit onto the board. Even if deck-building isn't usually your thing, if you love strategy and puzzle games you might even find this win you over.
This twist on having to position your cards, along with the enemies messing with the board too, just adds such a fun dynamic to the genre that I can't help but keep coming back to the demo.

Direct Link
Just some of what's been added to the fresh demo update includes:
- Eclipse levels for additional difficulty modifiers once you've beaten the demo.
- New encounters, including Astral Card Packs and new forms of infusing.
- Improved visuals for the player character and encounters.
- Even more, including starting boons, character mastery, run history, Astral Dust, new cards, and a lot of small quality-of-life improvements.
You can get a surprising amount of hours out of the demo with all of this.
I will be amazed if this isn't a big hit when it's released. It has Native Linux support too.
Another thing that's interesting is that the moon surface you're playing the cards onto is not quite simply uniform. You can be under attack by one or multiple enemies, and they are attacking zones of the surface, not the whole thing. If it's just one enemy, it's attacking about two thirds of the surface. But if it's like four, each one is only targeting like a quarter. This matters, because a defensive card will have a rune on one of its tiles, and for the defence to work, that tile has to be in the area being attacked. So that complicates your card positioning.
So far when I got new cards I was only really thinking about their overall size and about what they did. I suspect if I get better at the game I will start thinking in terms of how the shapes interlock.
Another thing I'll say about this is it feels quite atmospheric.
Last edited by Purple Library Guy on 13 Aug 2025 at 2:37 am UTC
Really atmospheric, and some nice synergies too.
It's missing some kind of relic system currently, which pretty much every deckbuilder implements (Slay the Spire, Roguebook, Monster Train, etc). Something to subtly (or fundamentally) alter the core gameplay mechanics if you're lucky enough to line it all up.
There could also be more in the way of upgrades. Right now, all you can really do is add an attack or defence rune to an existing sigil/shape which is a little underwhelming. I suppose there are also a couple of upgrades for overall damage and duration, but I imagine the final game will have more.
Great start, great demo, really enjoyed it. Looking forward to the final release now!
Something weird happened to me though . . . I had this card that was supposed to buff defence cards it was adjacent to, but that didn't seem to be happening.
Haha - I had a the same problem!! Turns out, you play that card first, THEN anything played adjacent will be boosted. They could make the language a bit clearer on some of the cards, for sure.
Edit to add - that's why the right-click to "ghost place" the cards is quite useful to plan out your turn. Especially if you're going for the "board fill" special trigger (the 2nd character has cards that feature this trigger - they're not worth in my opinion, but it's nice to see novel ways that the board can be a catalyst for effects).
Last edited by scaine on 13 Aug 2025 at 3:26 pm UTC
Thanks for trying out the demo! If you're interested in playing more, we're running a closed playtest though our discord server (linked on our steam page). We're always looking for more Linux playtesters -- you guys give the best bug reports and we want to support as many distros as possible at launch!
- Daniel, Snake Tower Games