If the 30 single-player missions aren't enough, Field Commander packs a war-chest full of multiplayer games. You can play two-player versus ad hoc or infrastructure, or using one PSP and passing the unit back and forth. You can even email moves through SOE's serverand see what the other person did in transmission mode (a slow process, but thanks for trying).
Taking this game online practically makes the replay value infinitely addicting. No matter how good you think you are, someone out there can stomp your ass into the ground - but totally fair, and in plain sight, so you can see what you did wrong. Online leaderboards show what's up, though mid-game dropouts were rampant in our online time. But that's the main catch to Field Commander - tiny, little things that pick at your brain.
Game-stopping bugs are never welcome, and we ran into two during our long campaign. First, the game just flat-out crashed on us, forcing a PSP reboot. The second is when we used the special ability "Nitro Boost." It asks you to choose a unit for the enhancement... but if you've moved all your units, the game doesn't stop you from making the mistake. You can't cancel the move - total hardware reset again.