Hyperdimention Neptunia Re;Birth 1 has a feature that wasn’t in the original PlayStation 3 release at all. Dengeki explains the PlayStation Vita remake uses the Godly Game Disc system from Hyperdimension Neptunia V instead.
One of the features that made the original Hyperdimension Neptunia unique and never made it into future games is players can make custom summons by picking an image saved on your PS3. These summons weren’t exactly more powerful than regular attacks and the animations too longer.
However, there was a novelty factor since you can put your face into the game or add other video game characters into Gamindustri. I have a bunch of summons of different consoles, for example. Sega also lent Compile Heart sprites for retro games like Fantasy Zone which are built into Hyperdimension Neptunia.
Compile Heart hasn’t said if this feature will be in Re;birt 1 or not, but it would be neat if they left it in especially since you can use the Vita’s cameras.