Fairytale Fights

Complete the game with at least one other player active on the Intermediate setting. The other player has to be present from the start until the end of the level for it to count.

If the host has already beaten the entire game once, you can skip certain levels to make future play-throughs quicker. Chapters that have a separate "Conclusion" entry in the selection list do not need to be done. So you need to all selections that are labeled "Conclusion" plus chapters 1, 3, 6, 8, 9, 11, 13, and the Epilogue.

In handy list format, this means the following 15 sections have to be played:
Chapter 1
Chapter 2 - Conclusion
Chapter 3
Chapter 4 - Conclusion
Chapter 5 - Conclusion
Chapter 6
Chapter 7 - Conclusion
Chapter 8
Chapter 9
Chapter 10 - Conclusion
Chapter 11
Chapter 12 - Conclusion
Chapter 13
Chapter 14 - Conclusion
Chapter 15 - Epilogue

The achievement will unlock at the chapter results screen for the last one you do. Note that the Epilogue's chapter results come after the unskippable credits - do not turn off the game before you see the results screen or you won't get credit for the chapter!