I watched the Cornelica anime and I can say that it's bad. Extremely underwhelming even for hentai animation. Don't believe anyone recommending it.
There's four episodes, all focusing on two girls each. So the game gives time to all the girls in the game (minus the robot guards), right? Wrong!
Half the characters are missing.
No Irina (the one with a suit), Justina (clothes seller), Vanessa (Lily's mom) or Verna (witch scientist). Not even cameos. Lily's mom could have been excused since it takes place after the game, but they could have used a dream sequence or a flashback without Al. The others have no excuse, so they were just being lazy In fact, the final episode is a rehash of the sex scenes from the second episode.
Lily is the worst part. She starts faithful to the game more or less. She is close and loving with Al and pulls him out of trouble when the succs take advantage of him, though she comes out as pretty pathetic when she takes so long to rescue him in some scenes. In the third episode the show suddenly turns her into a yandere who charms Al so he can't resist her, then fourth episode implies she's going to keep him with her forever. A cliffhanger that goes nowhere.
What made her different from the other succubi and made her relationship with Al so cute is that she truly wanted to help him and was always nice to him. Even though she's a bit lewd like every succubus, she loves him romantically and doesn't trick or betray him. Cornelica's a Dieselmine game, it shouldn't be hard to get what little story and characterization it has right.
Bottom line, just play game. The animation isn't even that good.