I know this may sound ASB (and it can be moved there if you want) the following happen:
* Germany enacts the full Schliefen Plan (including Netherlands)
* China joins Germany in order to gain Hong Kong from the UK, and Outer Manchuria, Tanu Tuva and possibly even small regions of central asia lost in the 18th-19 centuries
* Spain invades Portugal to unify Iberia, than joins Germany, due to conservative elements in the government, wishing to gain all of Morroco, Mali, Gibraltar and even 'hispanic regions' of FRance (ie French CAtalonia, Northern Basque and tiny areas with Spanish minorities).
* A major rebellion, backed up by Germans, arises in India, with the war going on for years.
* Britain coaxes Persia to join to gain against ottomans to balance things out and to challenge the Ottoman Caliphate.
I know some of these are very unrealistic, but through messing around on Darkest Hour, I wanted to know what would realistically happen if these events occured in terms of battles. It's not how they came to be I'm worried about, but hte consequences short and long term of what it would be. Good luck!