The OAV "Beat Angel Escalayer" is loosely based on the game, but lacks the masturbation. There is still Sayuka / Escalayer getting fucked by all the alien enemies, and of course sweet sex scenes between her and her close friend Kyouhei. The animation is one of the clearest made ever, as PinkPineapple took time in making this. Definately worth watching especially if you are a fan of the game. Two groups fansubbed it, but both botched stuff up. Just a note. Doki Doki should be translated to "arouse" in sexual context. All fansubbers failed to realise that "ecchi" or "H" is translated as "horny" and NOT "perverted". You use the word "hentai" to describe someone who is perverted, and usually you call women horny and not perverted. This brings up the commonly used slang term of calling a woman whom has an insatiable urge for sex a "horny bitch".

[from http://www.masteryoshidino.com/hentai/beat_angel_escalayer.htm ]