Unlocking planes and difficulty settings.

[Soviet Ace]

All we need, is someone like Anton or someone else who has the know how about what the deal is with unlocking. It's sorta hard to tell if things are unlocked on completing certain difficulties, (at least for me), since I've played the same mission on Campaign (Realistic and Sim) where you unlock the Yak-1, but have gotten nothing else. Maybe it's the mission? But I've done the other missions, where I would expect to get something. But I don't get anything? We really need a Dev's answer.