'Rengoku: The Tower of Purgatory'

With its sleek android hero and poignant story of his soul's tortured awakening, "Rengoku: The Tower of Purgatory" promised to deliver more than mere third-person hack-and-slash action when we popped it into our PSP. Unfortunately, it wasn't long before we felt like we were the ones trapped in Purgatory, suffering the same torments over and over.

"Rengoku" (Konami; $49.95; Rated Mature) seemed to have so much going for it, starting with a well-conceived plot set in a future where androids exist to serve humans, fight their deadly battles and serve up their entertainment. Part "Blade Runner," part "Gladiator," "Rengoku" presents a world where humans are no longer willing to risk death and have created vast armies of vicious android mercenaries to fight in their great wars.

Now that war has ended, humans have no use for these armed machines that can morph and adapt weapons to grow right out of their special skin but have no peacetime uses. So they come up with a brutal solution to thin the surplus: They lock the androids into a giant tower dubbed "Purgatory," and then entertain themselves by watching the androids fight each other for dominance.

It's not clear how or why one of the androids has become self aware, developing an ego and a longing to escape the carnage around him. But to win freedom outside the tower, he must continue to fight his way upward through its eight levels, slicing through legions of other lethal androids with the wicked blades embedded in capsules in his arms or firing bursts from the gun that erupts from his forehead.

The android ADAM, for autonomous dueling armed machine, has enough personality that you root for him when he assimilates a defeated opponent's weapons into his malleable "elixir skin" and ache for him when he loses a fight. That causes his body to melt, his acquired weapons to disappear and his liquid essence to flow back down to the bottom of the tower, where, like Sisyphus, he must start all over again.

And that's where "Rengoku" becomes frustrating. Sure, no one wants a cakewalk where you easily defeat every enemy or boss without a challenge. But all too soon, you grow weary of doing the same things over and over, shooting or melting, melting or shooting at enemy androids with few distinguishing characteristics.

There's too much trudging around here, particularly after you snag a nifty new weapon from the enemy you've just defeated. Your first instinct is to slip it into ADAM's body and try it out. But, no, you've got an inexplicable, irritating wait while you schlep back to one of the tower's terminals -- burning resources and risking more clashes -- before you can assimilate it into your own cache.

In addition to a single-player mode, "Rengoku" offers Wi-Fi modes to play and swap weapons with other PSP owners. Nice idea, but every time we tried it, we couldn't locate enough other players to get things going.

It doesn't help that the game is generally dark and visually boring. We didn't expect a premise this grim to be bathed in cheery sunlight, but neither did we welcome the headache induced by squinting at unnecessarily drab environments. Some androids and bosses are interesting but not enough to counter those dull, blocky walls, muddy textures and uninteresting square rooms.

Still, our desire to learn ADAM's fate prodded us to stick with him on his journey. After all that, we hated the ending. We won't give it away, but consider yourselves warned that you, too, may feel cheated at the top of the tower.