Mind Zero is, in the end, a game done in by its own averageness, which is a shame because it had some pretty interesting ideas buried in it. Too much of the game reminds you of its overall drabness, especially the actual dungeon crawling and encounters, which is probably the most damning part, because it is thick with random encounters.
The game isn't all bad. The general premise and aesthetic are derivative at first glance, but the theme of Mind Zero manages to be basically engaging, even if it's underdeveloped. The skill card mechanism of upgrading skills and spells is fairly interesting, using random skill drops to level up the ones you care about, but it sucks having to leave the dungeon to upgrade them, since it's a pretty major disruption to the game to trek back out to Yokohama when you fill up on skills.
The most redeeming feature of the game is that it has an interesting meter system. There are three meters, Life Points, Mind Points, and Tech Points — Tech Points power your skills, and Life Points and Mind Points fall into a kind of balance where LP is the health of your character and MP the health of your MIND, a Jojo's Stand-esque entity that you can have fight for you. Take damage in one form, and just switch modes and heal up. It sets an interesting kind of rhythm to some fights where you have to be careful with the meter management.
Unfortunately, the complicated balancing act of the meters makes the many, many random encounters feel all the more tedious, and it isn't really compelling enough on its own to make all the fights feel engaging. The game has some balance issues, as a mob of the right enemies can quickly drain your meters and leave you with rounds of recovering before you can get back to addressing the fight.
Additionally, the same meter system also makes solo enemies, including many of the later bosses, extremely trivial if you have a good party dialed in — the boss's damage output, even with the occasional special or two attacks per round, just can't crack through both meters fast enough to really be a threat. The last few bosses, including the two-phase final boss, were nothing but battles of attrition, chipping away at huge health bars while never really being worried about occasionally healing.
Otherwise, the game is an average gridder. You talk to your friends in the overworld, then dive into the dungeon, which has fairly average environments, mostly unmemorable music, and a disappointingly underdeveloped graphics engine. And maybe that's the hardest part of the game to stomach — compared to the wonderful Demon Gaze that came out just months ago, Mind Zero, by itself, offers so little, even if it has plenty of potential good ideas that never fully pay off.
The game pretty shamelessly ends with a setup for a sequel, which may or may not ever come as it was considered kusoge in Japan (an overblown label, in my opinion) and didn't do much better here in the West, but I do kind of hope they try another game, if they improve on it — the core idea is pretty good, and I do think they have the beginnings of some interesting mechanics to work with.
Ultimately though, I wouldn't really recommend for or against Mind Zero. Check it out if you feel interested, skip it if you don't. Not bad or not great, I kinda liked it, but it's a difficult thing to like.