If you can ignore the terrible RPG trappings, there's a lot to be said for the real meat of the game, the customization and battling of Custom Robos. Though it requires slogging though the main game for a lot longer than I'd prefer, once you've unlocked enough shops so that there's a real variety of parts on offer, customising your Robo is a pleasurably personal diversion, one that can lead to truly unique robots and battle styles.
The battles themselves are surprisingly fun, too. Though fetishistic big robot enthusiasts (the kind who were excited earlier with all that talk of robo-crotch rubbing) will probably kill me for saying this, Custom Robo Arena's battle engine is roughly similar to Virtua On, though far less precise. Unlike the strictly timed, angular battles of Virtua On, most fights in Custom Robo Arena are about as graceful as a fight between two drunks - one on roller skates with a super soaker full of wee, the other one throwing rotten fruit from a wonky trolley stolen from Asda.
Not to say that the battles can't be deeply tactical. It's entirely possible to modify your Custom Robo's parts directly before battle to better combat your opponent, with certain weapons better suited against others. If you know your opponent is packing some high jump legs and a close range drill gun, then you can increase your odds against him by using a gun with a long range that homes in on airborne targets, to keep him out of range and ensure he can't gain air superiority.
It's another sad failure of Custom Robo Arena's single player mode that all of these tactical nuances matter little as long as you're sure to purchase the latest, most powerful equipment as you go, turning even some of the hardest opponents into mere trivialities. Of course, the designers have chosen to put in unfair roadblocks to progress rather than challenge, so you can spend hours leveling up needlessly to suit character's whims just to progress through the plot. It's never particularly clear what "leveling up" really does for you, anyway.
Custom Robo's online capabilities make it somewhat worthwhile, however. Using a similar system to Metroid Prime: Hunters, you can quickly (and easily) battle random opponents, and also add them to your "rivals" list, a separate list from your closed friends list, which still requires a friend code. I've managed to play quite a few games against random opponents, and with the option to search for opponents who are roughly the same level as you, with luck you'll rarely face off against an opponent way out of your league. It remains to be seen how long the online world of Custom Robo will stay busy, though.
So, a horribly clichéd plot and a fairly tedious single player mode, but it does have a nice online mode and asks you to rub your robot's crotch to make sure it's working properly (if you're into that sort of thing.) Now, the most cliché score I could hand out is a seven, obviously, but unfortunately, that's one video game cliché that Custom Robo Arena doesn't get to have.