Only played demo, but from the outlook, game doesn't have enough realism or strategy
Compared to games nowadays, HOTP falls far short of the stunning graphics needed for a rating of 10. The planes don't look sleek, the sky doesn't look smooth, and the AI controlled objects look like a nice background instead of an interactive environment. In other words, HOTP has graphics back in 99 or 2000. Nothing looks interesting, since most of the objects in HOTP are bland and look 2-D.
Sound: 9/10
Well, the radio has enough fuzz in it alright. The engine sounds are as all engines sound like, and the gunshots have a nice 50's authenticity in it.
Gameplay: 6/10
Now here's the worst part about HOTP. From the missions I've played in the demo, there really isn't much strategy or simulation in the game. It's basically a shoot-em-up on a grand scale and with more freedom, since you get to actually move your plane in 6 directions. The annoying part in all this is that the objectives are far too narrow and unrealistic, such as: shoot down 100 japanese planes. When did ANY fighter pilot have a mission to shoot down 100 planes?!?! They'd be lucky enough to protect the goddammed battleships and the fleet itself! In short, the mission objectives have not realism, the mission themselves have no strategy, and flying the plane is nothing like simulation. It'd be a good game if you're into arcade-style flying shoot-em-ups though.