Updated:
No one seems to care about the actual gameplay specifics in the DB FigherZ thread so I'll drop this here instead
So it looks like Assists have a 5 second cool down. Each character has one assist. The assist are,
Gohan: Uppercut
Goku: Horizontal Kamehameha
Vegeta: Diagonal downward rapid fire
Cell: Diagonal downward Kamehameha
Freeza: Quick horizontal explosion explosion
Buu: Blows pink smoke in a horizontal direction
Assists can take damage but it recovers very very fast.
Characters have blue life which can be recovered while tagged out.
Despite assists recovering life very fast, tagged out characters recover life slower.
Also Tagged out characters have a cool down around 10 seconds before they can be used again as an assist
Raw tags are an attack like Marvel
DHCs are in
The game has push block
Looks like there is a homing dash ala Arcana Heart
You can spend a meter to do a teleport cancel which will put you right behind your opponent. This can be used to extend combos or used with assists for mix ups and punishes.
7 is the max amount of meter you can have.
Instead of X-factor it seems your characters just gain more meter when the others are gone.
This makes someone like Freeza with an install super very good in anchor position
There is some sort of Burst like mechanic called Sparking where you can escape combos and regain your redlife. Indicated by the little lightning bolt under the life bars.
Additional info with gifs can be found here.