From my perspective, Dragon Ball Z Dokkan Battle is a very fun game especially if you have friends that also play so you can compare collected characters and possibly have a few undeclared competitions with them. Since the game is NOT multiplayer, you cant actually fight them in-game, which is fine, but would be a really cool addition to the game.
Now to talk about the few flaws this game has. This is the Global version. The original version of the game is on the Japanese server(s?) and that is 6 months older/ahead of the Global version. The only upside to this is the ability to know whats coming in the future… for the most part.
Another flaw is that the game is not optimized for the newest generation of devices. Instead, Bandai is keeping the graphics fairly low in order to reach more people on older devices/OSs. This would be fine if they optimized the games images and graphics for anyone on newer devices. Its more of an inconvenience, but nothing too major.
The last thing Ill mention is the addictiveness. This game is structured to reward players who log in everyday at a set time. Since youre playing everyday, you may as well make some progress on your account. You do that, and you want to do more, but you cant since your stamina has been depleted. Now you go on about your day until you have some free time. Okay some more, get some more characters and things. The game progresses. All of a sudden, youre hit with a notification that a new banner is out and has some pretty nice characters on it. You go to summon, and what do you know, you summon nothing truly usable. You summon again, and now you summoned at least one decent character, but its not the character you were looking for. You summon again, and like the first time, you get nothing. At this point you run out of Dragon Stones to summon on this banner. The banner is ending soon, so you need to get more stones and quick. Rather than spending an hour of your time, you decide to buy a couple of stones. Whats the harm? With your newfound stones, you go to summon, and you get the character you wanted. Good job. You get to a point in which youve spent so much time trying to play the game well that youre returning the moment you have more stamina, and for the more extreme, only once youre finished with whatever you were doing. If you decide to play this game, keep this poorly written story in mind. Of course you may become more of a casual player, and thats fine, but you WILL lose interest within a month or so.
Overall, Dragon Ball Z Dokkan Battle is a fun game and a pretty decent time-killer if youre looking for one.