Chronos Twin [GBA - Time Travel Action - Unreleased]
http://www.unseen64.net
"Chronos Twins is an action-adventure game set for European release in early 2007. There has not been an announcement for any North American release. The game will put a different perspective on time travel than most games. Instead of revisiting an area in two different times, both screens show the same setting during two eras as gamers explore the land with a present-day hero. Chronos Twins was originally planned for release for GBA, but after the Nintendo DS rise the game has been ported to it. The lack of use of the DS capabilities is the reason for the low release price.
In 2004, the GBA version was cancelled due to the publisher's fear to legal disputes with Capcom, after graphics rips were discovered on Capcom BBS and other Internet forums violating Capcom's Copyrights. Three Wonders, Marvel Vs Capcom and Magic Sword graphics are still visible on the released videos in the major gaming websites. Surprisingly enough, the publisher's website still shows GBA screenshots on their game's website." - [info from Wikipedia]