By Blood Alone does for aviation what other expansions had already done for ships and tanks, and along the way overhauls Italy and adds the long-requested peace conference system.
Nations and Content
Italy gets a completely overhauled focus tree, with more depth for both the fascist path and alternatives. Ethiopia and Switzerland get their own playable content with some real substance for the first time.
New Mechanics
The plane designer lets you build fighters, bombers and naval planes piece by piece, just like you already could with ships. Peace conferences give you more control over how territory gets split when you win a war, instead of leaving it to an automatic resolution. It also adds unit medals (to boost morale and performance of veteran divisions) and an economic embargo system.
Is It Worth Buying?
If you like customizing equipment in detail, the plane designer is just as substantial as the naval or tank ones. And peace conferences, being a general system mechanic, change any game where you win a major war — you don't need to play Italy to notice it.