Katja's Abyss: Tactics is a turn-based tactics game with minesweeper-inspired mechanics and pixel art graphics. Creates and control mining units in a cave, mining for energy and defending against warped monsters that appear in the darkness. Play in two modes: Campaign and Infinite. In Campaign Mode, follow a story across 8 authored levels with unique mechanics. Infinite Mode has multiple difficulties, and each time you complete a level, you automatically move onto the next. The high score of consecutively completed levels is recorded on the title screen. In both modes, find collectibles that hint at the lore of the game world.

In the campaign, your supervisor Katja van Loode, Head Researcher at Echo Mining Corp, guides you into increasingly dangerous sectors of the mountain Montmane. Although she gradually trusts you as a captain, she consistently refuses to give you much information about what her intentions are. There is evidence that some of her decisions go against headquarters' orders, but she continually keeps you in the dark. It seems these caves hold many secrets yet uncovered. Will you follow Katja to the end in hopes of answers?