I never played it, but everything I saw from it really reminded me of Hyrule Warriors if you ever played/saw that game in action. Basically, its an action title with role playing game elements (you level up, store up health restore items, ect) and you play as familiar Dragon Quest characters across the entire series. The game looks fantastic on PS4, runs quite well and with the amount of leveling up you will be doing the game can last a very long time.
I guess the best thing I can say is that if you liked Hyrule Warriors or enjoyed whatever you saw of the game, this is a larger version of that title if that makes sense.