It's addictive. I love the games and the sprite art is amazing. The music is catchy, and Gunvolt himself controls pretty much like a dream. It's by the creators of the Megaman Zero games I believe. And damn it's fun.
But it can be frustrating when you try grinding for materials to make better gear. You basically have to speedrun and kill all the enemies in a similar fashion to get a high score. And basically not get hit at all. It's fun for speedrunners (I love getting S+ ranks in the missions) but for the casual player, it could get tedious grinding for items to help you air dash and double jump etc.
In Gunvolt 2, playing as Copen is actually better for speedrunning since he can pretty much keep moving forward. Whereas Gunvolt has to stop and electrocute people for a few seconds before moving onward.
The voice acting is good. But I don't speak Japanese so maybe it's bad to Japanese people lol The writing is awful. The story itself is half baked. But the characters are pretty cool. Too many little girls but that comes standard with anime style games I guess.
Anyway. Sorry for the long comment. 8/10 game for me. The story may be kinda dumb but the characters, music, and ESPECIALLY the gameplay more than make up for it. I'm not gonna be buying the Switch version cuz I already invested money and time into my 3DS versions