"Marble vs PC"
Story:
Superheroes argue, which is more important strength or intellect. They are separated into two groups:
"Marble" is for super strong and "PC" for super smart.
Only Duggy can help them sort that out.
Gameplay:
In each mission you have to decide, whether you want to solve puzzles, or dig through high level tiles.
Depending on who you helped more. In the end, you get camp equipment.
PC that give you capacity, or Marble that give you regeneration.
"Marble vs PC 2"
Story:
Next year things are escalating. Diggy must stop them, from starting full war.
Gameplay:
Diggy using, giant rocks and doors. To stop "PC" from getting to battlefield.
Lasers and teleportation devices, to prevent "Marble" to enter fight.
Marble vs PC 3
Story:
Year after that. Huge threat appears. Diggy must unite all heroes. That's the only way we can survive.
Gameplay:
Finding heroes and doing small tasks for them, to convince them to join "super hero alliance".
Finale is big level, that requires solving puzzles and digging through high level tiles.
P.S.
And add some giant marbles, that cost energy to push. Just to justify name of event.