The main problem I had with this game was it got boring, fast.
Graphics - You can't expect much from a GBA game, but this is actually pretty sad. Alot of other games pull of better graphics than this. Even the LoG series had better graphics, actually overall they were MUCH better than this. Sad.
Gameplay - This was the worst part. Boring, boring, boring, and BORING. You know, when I played the first level I actually thought, "Hey, this might actually be a pretty good game." However, 10 minutes later I realized how wrong I was. This game got repetitive, FAST. Hmm let's see, punch, kick, POSSIBLE special attack, then charge when nothing is around, punch, kick... You see where I'm going with this? Truly this was the worst part.
Sound - I heard a few seconds of sound when I first started playing, but then I turned the volume down and just turned on the TV. Yeah, it's that bad.
Replay Value - Well there's a little I guess. You'll have to play through the game to get extra stuff like Super Saiyan mode (Shouldn't they already have that?) and SSJ4 Goku (You can play as Kid Goku.. and Kid Goku transforms into this form so... why is SSJ4 considered a separate character?) and some others, but as you can see there isn't much there.
Overall - Pretty much, it's horrible. I would advise you not to waste your money. MAYBE worth a rental, if you want to get out of DBZ forever. So yeah.
Don't buy it.
I apologize for any possible spelling errors.