Starvoxel: Defender is a portrait merge tower defense built around one shared star. You protect one lane while an AI ally or a second player protects the other, and every leak damages the same shared health pool. Summon defenders, merge matching families and rarities, evolve Legendary units, and build a seven-family loadout. The current Android release includes 14 defender families, five battlefields across a 60-wave run, boss challenge waves, packs, and permanent card upgrades. It is free to play with no ads or pay-to-win.