Do you like Dynasty Warriors? If you've never played it, I guess the easiest way to describe the game would be like Diablo, where you have a lot of enemies on the screen all at once, and some maps have objectives you need to complete in order to complete the map (such as don't let X take damage).
If you enjoy any of the "Dynasty Warriors" titles or any of the other Koei-made "Musou" series titles (there are tons out there such as the Nintendo WiiU / 3DS "Hyrule Warriors",), I think you'll probably like it. Know this is not a "mainstream" Dragon Quest game at all, and simply uses familiar characters, enemies etc... from the series to tell a new story, but the gameplay is decidedly "Warriors" style hack and slash, with a RPG bend to it in terms of weapons, character growth, and unlocking of various missions/victory conditions etc. Compared to other Warriors titles DQH had more RPG elements which some will enjoy if they're into JRPGs. Its notable that DQH itself was a single player title, but the sequel is poised to offer co-op which is nice. Hopefully it will be fully online co-op for PC done right, because Musou/Warriors titles can be great fun with a friend.