RAY-GUN

Georgie is a young man who lives with his fiancee Miria in the quiet town of Lakeside, repairing large combat robots which are strangely called "steroids". One day he discovers several such steroids in the forest, and as he decides to inspect them, unknown flying steroids kidnap Miria. Now Georgie has to pilot a steroid himself and to rescue his beloved one.

Ray Gun is a traditional Japanese RPG, with top-down navigation, random turn-based battles viewed from first-person perspective, etc. The combat is usually between the player's steroids and enemy ones. Steroids can attack normally or execute special techniques. Many cut scenes feature nudity.

[From MobyGames]