Is the second game any good? I've seen some mixed reviews but nothing indepth.
Having played some story, PQs, and mentor stuff, I can now safely say it's much better than the first game already.
I'm not great at reviewing stuff, but I'll try to cover the biggest changes I can think of between the first game and this one.
The hub is much bigger than the one in the last game, but also manages to be far less empty; there are tons of NPCs around, some with their own mini-stories going on, some that give you new emotes if you use specific emotes on them, some that ask you to bring them certain items and will reward you in return, some that'll challenge you to 1v1 fights and give you rewards for beating them, etc. Also you can find some consumables and accessories lying around the city. Overall much more to do in the hub.
Mentors are no longer random; once you unlock them, they will always be at their spot on the map. You also no longer need to fill up the friendship gauge with them to learn their moves (though it is still there, I haven't found the use for it yet). You now have an overall "class" gauge that goes up when doing things like mentor lessons, taking your mentor on PQs, etc and when it's full you can take an advancement test to unlock the next tier. Like you start off with access to Tien, Krillin, Yamcha, and Piccolo, and you can do like their first 1 or 2 lessons right off the bat, but you'll need to do the Easy advancement test to be able to learn the rest of their stuff (and I'd assume to be able to start with other mentors). Also, you no longer actually need to have someone as your mentor to take their lessons; you can just stick with your favourite mentor and do everyone's stuff regardless.
Combat is much improved too, with step vanishes being much easier to use and much more useful this time around. There are now chase mechanics if you want to continue a combo after knocking an opponent away, and there are new stamina break attacks that have a long wind up time, but will completely break the opponents stamina provided they don't block the hit.
Some super and ultimate attacks now have bonus effects, like x4 Kaioken Kamehameha uses 3 ki bars to use, but you can activate it again during the attack to spend an extra 2 bars to throw out an extra burst of energy for more damage.
Oh, and AI allies are no longer completely useless; I had Nappa and Vegeta practically clear PQs without me.
That's all that comes to mind right now, but I've only done 10 or so missions so far so I can't speak about things like transformations or expert missions yet.