Even though the missions are shorter now, Heatseeker's biggest problem is that its gameplay is still repetitive. It's also not particularly original either. The game's not terribly difficult on the default setting, and there are plenty of checkpoints. But sometimes you have to repeat an entire level because something you're protecting has no health left when you start at the last checkpoint. Even then, except for when enemy planes repeatedly avoid your missiles by releasing flares, you'll rarely find yourself too frustrated. One thing the PSP version has that other versions lack is multiplayer. Up to four people with their own copies of the game can take part in five different game modes, ranging from a normal dogfight to a team-based mode where you must defend your base while attacking your opponent's base.
Other than some decent-looking clouds and a generally solid frame rate, there isn't much to look at in Heatseeker. The levels are large, but they're mostly empty, and what is there is ugly. Buildings are little more than blocks, while the ground is an unsightly, poorly textured mess. The ugly graphics are particularly problematic when flying over water, which almost completely lacks detail. Because it's always a big, blue blob, it's difficult to tell how close you are to taking a bath, and you'll find yourself often plunging into the water. The planes look OK, but other than your craft, you won't get much of a chance to look at them. Explosions aren't bad, but the "impact cam" that shows them off via a quick movie-style replay after a hit gets annoying quickly because you're often in a different orientation when you get back to flying. There's also no in-cockpit view, which may be disappointing if you're looking for a more realistic view of the action. But to be honest, you'll probably find many other things to be disappointed about first.
Heatseeker sounds about as good as it looks. The amateurish voice acting from the console versions is gone and has been replaced by captions that pop up at the bottom of the screen. If you thought it would be easy to read captions while flying a plane at 800mph, well, you're wrong. The cheesy guitar rock that plays in the background during each mission would have been perfect...if this were 1985.
With subpar graphics, poor controls, and some unoriginal gameplay, Heatseeker has a lot of things going against it. But in spite of all these issues, shooting wave after wave of generic enemies can be fun in short spurts. If you're looking for some mindless fun, the game might be worth the $30 price tag, but be advised: There are better flying games out there for the PSP.