It's not canon. It contains an original stand-alone story (combining the virtual game premise with elements from the Time Patrol storyline) and a port of some of the arcade game's levels (including the Dark Empire Saga and the start of the Prison Planet Saga).

The other games aren't canon either for the record, they all tell their own stand-alone stories.

Ah, I was under the assumption that each mission was part of one storyline that made up the Dragon Ball Heroes series. Thanks for the help.

Each source of dbheroes media is only canon to itself.. for example the heroes manga series is only canon to the heroes manga series, the videogames are only canon to themselves and the anime is only canon to the anime.

Each mission is part of a larger series. But only the Arcade version of said missions. This game isn't canon to it.