Dragon Ball: Raging Blast 2

Its definitely accumulative, I dont have any actual figures but I know nobody has to be a speed demon to do this, so just take it easy and it will come in due time.

It turns out each of these solutions is wrong, and this achievement actually comes down to perfecting each different row at least once in your time playing the game, not a specific number of rows completed.

There is around 8-9 different sets and one would have more luck letting the main menu idle as TIR said or play on multiplayer as those load screens are a bit longer as well.

Credit to the discovery goes to scooterrdabest3eva on youtube.

Ok, I just got this achievement a few moments ago somewhat randomly (I'm not connected to XBL for at least another week so it won't show till then), and I was being somewhat lax about pressing the buttons on the screen after doing it many many times before. When it popped though, the fight had just loaded immediately after I made an "explosion" of many balls from getting the first and second sequence right.

That tells me this achievement is one of two things: 1) it's cumulative and it'll just take time and muscle memory to get it (by this point I had finished Galaxy Mode, got up to Triangle Zone in the Battle Zone and had fought several times online and offline with custom battles as well as doing what TIRtheMaster said a few times and used the loading screen for the demo to see if it was in one run, so it would take quite some time), or 2) you have to end it with an "explosion" of Ki balls, probably from one or two sequences.

Hope this helps making this achievement more clearer to comprehend

Ths envolves the loading screen and u either need 2 hit the buttons extremely fast or do it so many times over time no one really knows rite now but it is either 1 of those 2

From what I've seen no one quite knows how to get this. But we do know it involves the loading screen, and I just thought I'd post the longest loading screen is when you're waiting for the demo to load from the title screen.
Edit: Syrkailler has informed me that this is cumulative and it takes about 150-200 lines to unlock.

Without a doubt, this is a cumulative achievement, not a test of whether or not you complete each line. I kept careful track of which lines I had and hadn't completed and was worried when the achievement didn't unlock (especially since I was nearing the end of Galaxy mode). However, the achievement finally unlocked after I completed an easy line I had completed many times (A,A,A,A,A,A,Y).

For me, this achievement unlocked after beating every character up to Android #14 (I had only 100% completed about 5 characters). Like the above guides state, this is unlocked during the loading screens inbetween fights. Focus more on accurately inputing the button combinations, rather than doing them quickly (as half the time I could only doj at most two lines quickly before the game loaded a battle and barely a line after returning to the menu).

As long as you try to input the buttons on the loading screens, you'll unlock this in the course of the game. Keep at it, as it will take a good while for the achievement to unlock. Good luck.

Don't worry, this achievement is cumulative, just keep pressing the buttons on the loading screen. It does not need to go beyond 2 sequences or 3, as described in the guides above.