You can't possible just mean the anime art style right? Because that is like 90% of them.
If you truly are unaware, I suggest you go to dlsite and look at games. This is a paysite of course so you can only look up the names.
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English, you can understand the menus, but getting titles in english can be subpar if the game torrent is in Japanese. This is the Japanese site
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(a trick could be to look up a game on the English site, find the circle name which is useually the same in english and japanese, then look up the circle on the Japanese site to find the Japanese title of your game)
Afterwards you find a torrent for games you like. A place that has adult anime / game titles is
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Off the top of my head, some great visual novel games with anime characters are the classics Bible Black and Discipline:the last crusade (Every hentai enthusiast should know these)
Dark Grimoire looks like a visual novel, so you should be able to find tons if you go to mangagamer
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This is a great site, because you will know every game is translated. Use the same method as above, find the title you like, then search the torrent on nyaa. (honestly, you should probably go to mangagamer before dlsite if shuffling the japanese and english is too advanced)
If I completely misunderstood your intent and you are looking for stuff similar to dark grimoire as in no sexual content, some great visual novels I can recommend are danganronpa 1 through 3 and Zero escape: The nonary games.
If you don't know how to download torrents let me know, also if you find an interesting game on either site, and you can't find the torrent I will help you out.