Until We Die is a base defense strategy game. Your base is the subway station, it's underground part. You'll have to defend it against all sorts of things, brought in by meteorites.
To win, you have to survive for about 30 game days, fending off all the attacks on the base. At first, it'll be small packs of creatures, and by the end, you'll have to fight a sweeping horde of mutants. Also, the game will end early if our hero, Ivan, dies or if the power generator, the heart of the base, is destroyed.