密室のサクリファイス ～イトカ：ある閉鎖施設からの脱出～

Jitka, one of the characters from D3 Publisher’s trap adventure game Misshitsu no Sacrifice, has awoken from a cold sleep and she’s trapped in an underground facility. In Misshitu no Sacrifice Jitka: Escape from a Locked Facility you have to help her get out.

Siliconera

This spin off plays like a "locked room" style game, with a focus on ecchi unlike it's predecessor.