Like many real-time combat games, has you start small and work your way up the ladder. Choose from one of seven seas to fight in, then maneuver and engage larger ships while collecting gold from defeated opponents before pirate raiders do. As the levels go by and you stash away more gold, you can upgrade your ship with additional cannons, better sails and heavier armor; you can also unlock more powerful ships, each with their own unique strengths and weaknesses. (A lets you sample the game with fewer stages and less powerful ships.)

WarShip presents all of this in a classic top-down view that zooms in and out of the action as necessary. Good graphics meet great audio work and a capable physics system, while responsive touchscreen and tilt-based controls lend a feel of urgency to the game.

WarShip uses a stick-and-carrot system that both helps the game and hinders it. While it's terrific to finish a sea and unlock a new, more powerful ship to pilot, the game places you in a situation where you must continuously upgrade even the most spiffy new ship to stand a chance at beating the current level. Though this keeps you coming back for more, it becomes a grinding process to reach anything new. Hoping that the next ship you defeat drops a few more treasure barrels can get old quickly.

Even at its current version, WarShip still feels like an incomplete effort. Although the game runs well under the iPhone OS 3.0 update, bugs crop up. In my testing, the frame rate occasionally became stilted, my ship's cannons sometimes fired at the wrong target, and colors appeared washed or distorted. In fairness, the developers seem to listen to user complaints--an almost-impossible first stage was made easier when a recent update lent a computer-controlled ally to fight alongside your ship. Still, odd leaps in programming logic, such as being unable to sell your previously-purchased boats in the store, will make you wonder what's going on.

Even with these shortcomings, WarShip proves addictive--it's fun to take on larger and larger targets as the levels progress. Despite needing touch-ups (and desperately needing a multiplayer mode), your finger wanders back to WarShip on the iPhone's Home screen and you start to wonder how things will be once you earn that frigate you've been saving for.