A shallow and unsatisfying experience.
Had Sky Heroes focused on refining the core gameplay and multiplayer support, this might have been a Mario Kart beater. Instead, the developers have seen fit to tack on an unnecessary and annoying story mode, in which you are subjected to pages and pages of unskippable and interminable dialogue all delivered in "goo goo gaa gaa" Sim speak.
If you want to unlock new planes and parts, then ploughing through the story mode is your only option, although most of what you can unlock is purely cosmetic anyway. Multiplayer is fun at first, but with no new areas to unlock or incentives other than an online scoreboard, it stops being interesting after a few games.
If there were an award for most inappropriate game music, then Sky Heroes should win hands-down. In fact, the whole game stinks of being designed by committee, none of whom talked to each other until it was complete.
And it's a crying shame. Because, at the heart of Sky Heroes is something very cool. The graphics, art direction, and sound design are top notch and the varied environments are lush. The range of power-ups and weapons is impressive, and it's fun to customize your character and aircraft. However, on top of the gripes already mentioned, the flight physics don't feel believable, collisions are too forgiving, and combat soon becomes predictable and repetitive. More time spent on getting this part right could have led to something exceptionally good.
Disappointing.