I had a great time with a couple card battlers last year, Cobalt Core and Nitro Kid.
Cobalt Core has a similar presentation to FTL, with a turn-based format instead. Plenty to do in it, great soundtrack, charming writing.
Nitro Kid is on a more traditional 2D grid with an isometric viewpoint. It appealed greatly to my love of 80’s settings, but I’d wait for a sale as it’s thin on content.