Simply amazing! As an avid fan of Ace Combat (since 2004) this brings back such beautiful memories, and I'm getting chills from just how beautiful this game goes. Sound design is well done (the BRRRRT from the cannon is just awesome, though the engine sound could use some work), graphics are beautiful (don't forget to add shock diamonds in the afterburners for better visuals), and runs pretty well, getting 70+fps average on maxed settings, though I wasn't paying attention to the counter that much :P (i7-6700HQ and GTX 1060). And that's all while it's in Alpha, astonishing! The Su-27 alone is already pretty awesome to fly, can't wait for your next update!
P.S. would be awesome if you bring an Ace Combat plane like the ADFX-02 :D