Waifus Attack

Monster girls hit the island out of nowhere, and now you're stuck there with everyone else who didn't get away in time.

The setup is straight survival first, mystery second: find a way off the island, track down other survivors, and figure out where these creatures actually came from. It borrows its structure from Suikoden, so the people you rescue aren't just background noise, they join your base and become part of what you're building.

Play is turn based combat layered over that recruitment loop, with a male protagonist leading whoever he's managed to pull together. Along the way there's the expected groping and teasing from the monster girls themselves, but the game leans harder on exploring, gathering survivors, and growing your base than on any single scene.