2.0 update, got some achievements out of open match being available to one person now. Still waiting for the new DLCs to not be so pricey, I'm not in a hurry
Pain, suffering, practice, and more pain. Had to beat the whole game without running out of lives. Everything was practice for that. The winning run had me deathless until the second to last world, with 5 lives remaining.
1CC, becausde this was the only way to reach the final levels in the first place. Blind stage 5 and 6 once I realized being speedy was the best option.