http://lusterise.nexton-net.jp/product/exs-tia/
This visual novel called Exs-Tia (or Ex-S Tia?) is coming out in a couple of months. The artist is Inoino (one of the guys who does the Sailor Moon Dark Planet doujins). The preview CGs don't really look like much at the moment. It's a pretty generic magical girl H-game where all the combat occurs in a rock, paper, scissors simulator. If you lose a fight, you get a standard girl vs. tentacles scene. There's also a rival magical girl on the aliens' side, but it looks like she's evil to begin with and wasn't converted.
But there's a pre-order poster that seems to tease one of the game's endings. You be the judge.