Here is the full list of all 12 QIX++ achievements worth 200 gamerscore. It takes around 6-8 hours to unlock all of the achievements on Xbox 360.
Defeat a total of 5 QIX.
Defeat a total of 30 QIX.
Defeat a total of 100 QIX.
Defeat a total of 100 Sparx and Pawns.
Obtain 30 points in Ranked Match.
Obtain 300 points in Ranked Match.
Reach a Cleared % of 95% or higher on eight separate stages.
Upgrade every Customize Screen parameter to the maximum level.
Clear Section 1.
Clear Section 2.
Gain 2,000,000 points in any Section.
Gain 3,000,000 points in any Section.