Story/Characters: The main problem with this category is that the game assumes too much knowledge. It was clearly intended for people who are fans of all three franchises (Gundam, Ultraman, and Kamen Rider). Characters are barely introduced, backstories are assumed, and a lot of what goes on is either a parody or combination of elements from the source franchises. If you don't know each franchise, you're going to be confused a lot of the time. The main plot is run of the mill.
World: There are three continents, one for Kamen Rider, one for Ultraman, and one for Gundam. Unfortunately they all look the same. Every town looks the same, and the dungeons are all almost the same as well. You can't tell which continent you're in just by the look of the area.
Game Flow: For the most part this isn't a problem. It's usually obvious where to go next, and the difficulty is fairly steady. Even in the annoying single-character parts of the game I only had to do a little bit of grinding.
That being said, it does get repetitive. All the dungeons feel the same, and because the plot is largely a series of episodes, it doesn't necessarily feel like you're making narrative progress.
System: This is a basic attack-technique-item-defend system. Each character has a variety of techs they can use in battle taken from the shows. Unfortunately they're poorly balanced and the higher level ones cost too much TP; there's also a lack of variety. One unique feature is that TP can only be recovered by using items (non-buyable until the end of the game) or by attacking in battle. Even resting at the hospital doesn't heal TP. This can be a little annoying when you need to refill TP after a boss battle, but it does allow you to use your techs in battle without feeling like you need to save it all up for a boss.
You cannot revive a character defeated in battle, which means that lucky critical hits or enemies with multiple attacks per round can screw up your chances. They'll come back after the battle with 1 HP but that's no good in a boss fight.
Side Quests/Optional Content: There are a few hidden things at the end, but that's it.
Interface: An average mix of annoyances and decent things -- you can't see the strength of items in the shop but the more expensive thing is better. At least they do have one button control for talk, open chest, etc.
Graphics/Sound: The graphics remind me of RPG maker -- as I said above, they don't distinguish between the cities at all, and the Kamen Rider and Ultra characters all looked the same to me. Average for this time, I guess.
The music is not good. The entire OST has only 16 songs, and 5 of those are for the title screen and ending sequence. 1 is the game over music, 1 is used only in a single story scene, and 1 is for the final boss. That means that 8 songs are the majority of the game's music, and you'll be hearing the same tunes over and over again.