After a year long beta the digital card game from Bethesda and Direwolf has finally launched. It is set in the Elder Scrolls universe, featuring all the various races and lore (important historical characters and events). It's aimed at a competitive audience, with much less RNG and more mature theme than Heartstone or Eternals.
Some of the unique features are PvE content - starting with 20 mission solo campaign serving as a tutorial for the game, during which you'll learn the ropes and build your first 6 or 7 starter decks (your choices during the campaign influence which cards you get, which is a nice touch). There are more campaigns coming in the future. There's also a solo arena, which you should hit after the campaign, where you can battle AI opponents to extend your collection (it has some nice rewards) and see how some combos and deck archetypes work. You can also play practice games vs AI and craft cards you need (disassemble those you don't need or have extra copies of and use arena/practice/pvp rewards for crafting).
For PvP there are arenas, casual and ranked play (I advise against going into ranked early on. It's not possible to farm noobs in this game like in Heartstone, it's damn hard). Ladder is reset every month, with people dropping in ranks to previous "breakpoints", ensuring a healthy meta and constant struggle.
In the future they plan on releasing structured in-game tournaments, spectator mode and so on.
The game is completely free to play, with the ability to buy extra booster packs (no need for that since arena rewards are decent enough to build your collection quickly - especially in pvp arena, but that's hard).
I've been playing this game since January and I've been having a blast so far. Managed to reach rank 2 in the ladder (you start at rank 12 and can go up to legend, which is rank 0) and gather about 94% of the core collection since then (could have 100% but I'm a sucker for foils and instead of getting cards I don't have I spend a lot of crafting resources on getting premium versions of the cards I like).