Have you seen Retro Game Challenge from XSEED? I just found out about it recently. You might glance at it and write it off as another DS-based collection of old 8-bit NES games. But man, you'd be wrong. These aren't actually old NES games! Observe.
What this game is, is a bunch of faux-8-bit games that attempt to capture the spirit of that era. They're all wrapped up in a weird metagame that has you bouncing from one game to the next, attempting to complete specific challenges--almost Xbox Live achievement-style--in each one before moving on to the next one. Sounds pretty clever and inventive to me, and it's all based on a Japanese television show that uses basically the same concept.
Retro Game Challenge is out next month. Look for it!