I had a crack at this VN on the DS a long time ago, but never got very far into it. I was tempted back to "The Nonary Games" by significant changes to gameplay to make it a little easier to get through all the endings.
The changes are excellent and allowed me to crash through it in a rather fun long weekend. No particular gameplay innovations (beyond a couple which are a bit spoiler worthy, so I'll leave them out).
It's got a solid puzzle base, with them mostly achievable within what I consider a reasonable time without massive amounts of guessing. And they're all nicely self-contained, not having that frustrating need to seek external information that some games rely upon.
The story is interesting, with a couple of good "what" moments and enough twists to remain entertaining. It also gives a nice justification to the usual "go back to get the best girl" system.
Recommended.
Tagged: Game Visual novel 2D Easy difficulty PC