パロスペシャル! 王位争奪戦

Underground military base is visited by the princess. Unexpectedly alarm is triggered and base becomes sealed while regime enemies show up. Main character needs to protect the princess and manage to escape in a week's time, or she can't attend coronation and conspiracy faction takes the lead. Luckily all the base personnel are women, so it may be possible to find non-violent solution for some of them.

[From vndbreview]