Dai 3 Ji Super Robot Taisen Alpha: Shuuen no Ginga he

Huger, epicer mash-up between several dozen super and real robot mecha series. Generally considered to be one of the better ones in a very, very large series stretching from the NES to the PS3. That said, it's also way too easy. At least it doesn't punish you for getting skill points this time.

Unused Attacks
The huge brown egg that the last boss is inside has a map weapon that never gets used, but is fully functional.

Unused Robots
In the game data there is a Grungust Sanshiki and several sprites for Gundam Sentinel robots that were apparently canned when the creators of the game were ordered to instead include Gundam SEED robots.