I'd recommend Legend of Mana. Very pretty graphics, wonderfully charming little stories, and not at all difficult. The only hang-up is that the world-building system is pretty random, and the game experience is much smoother with a walkthrough. You can still get quite a few of the stories with no walkthrough, but it won't be nearly all of them. There's also a pet-raising system and an orchard, so there is a little bit of the Harvest Moon feel there (I'm guessing, never played a HM game myself).
Katamari Damacy might be a bit fast-paced for her, wonderful as it is.
The first Spyro game is not a bad idea at all. It's a platformer, but it's very easy-going, one of the least difficult 3D platformers I've played, and there's plenty of collecting to do.
And if she has a serviceable PC, something like Curse of Monkey Island would probably be great.
|