However, I don't really think the idea is that new tbh. Take Ariane, in the hot tub and in the couch you have to 'work your way' to the end reward. And almost all the [no]click[/no] meet 'n fuck games you have to massage various body parts. Even Shark has this feature in quite a few of his games (and probably the best implementation of it)!
Going to the movies. I'm surprised that none of the dating games so far have done this.
Actually you're partially wrong: School Dreams 3? The best 1st date to take Molly to is a romantic comedy movie (don't recall how you're supposed to know that's her favourite)! But I'd have to agree that taking the girl to the movies is way under utilized.
I think a few of the ideas above would work best in a text based game. I've only ever played School Dreams 3, but I could see some of this easily implemented in that environment (and in fact some of it is! Take Becky to the cinema and try rubbing various parts ;)). It does lack the slow incremental approach though. In SD3 with Becky you can go directly to the 'good' part and if you bring Molly, you can do a limited selection of actions but in a completely random order.
Making a girl dinner could be used in varying degrees. Do you buy steaks, chicken, fish or vegetarian? potatoes/rice/pasta or just vegetables? Excellent task for a second date btw. PC takes her to dinner on first and has to remember what she ordered. Deduce from that what she likes and make something not too much exactly the same as she had at dinner.
Also did you have the dinner ready too early / just in time/ way too late, properly cooked / semi raw / burned. (mouse timing click check? eventho I hate some implementations of those)
Mood points for getting it right.
Take her out to a Concert? Assuming she prefers modern pop/rock: techno will make her think u're a freak, classical=boring (Perfect if you're bringing Kelly from VDG ;)), heavy metal = just mad.
If you want to make it really complex even picking her up could be made an issue (oops come to think of it .. someone mentioned this above I think): Do you take a cab borrow your dads Mercedes Benz (both good options if she's high class snob, not so much if she's to and through socialist or hardcore environmentalist) the neighbours Toyota Prius or WV Lupo 3L (She's has read in a survey that a 3L isn't really more ecological and laughs at you*), do you simply walk / take a bike (her bike gets a puncture, did you bring tools, and do you know how to fix it?) or do you go by public transport. Games where you take her on Multiple dates could prefer that you select different options for different dates (e.g. the bike for going to the beach - you couldn't get a parking lot for xx km and she got too tired from walking and then too sunburned from falling asleep ... ).
Cleaning up your house/apartment: Leonizer has used this once or twice, and probably someone else out there as well, but even this could be developed to some extent. IE. do you make sure everything is completely sterile (She might think you're a freak or that you don't actually live here) or do you just throw the dirty clothes in a drawer (she accidentally opens it).
What about your computer? (she uses it for a second to check the bus timetable and stumbles upon your adult movie collection / she types 2 letters in the address bar and the brower suggests www.sharks-lagoon.fr ;) and finds it comforting that you're only human / takes offence / gets worried what type of pictures you have since you had to remove ALL of them)
... I'll post again when I come up with more ideas.
* DISCLAIMER: not a fact I have from anywhere, just a suggestion. However, I'm sure you could find such a survey! If not in Greenpeace's archives then in the oil company's!