GRave Defense, as the title suggests, is a Tower Defense game on iPad. The "grave" reference has to do with the enemies you'll be facing, ghouls and creatures from the dark side that are massed against your (hopefully) superior military might. Yes, the zombie-themed game - like its source of inspiration - refuses to die. At least this one branches out a bit from zombies and offers beasts and creatures of storybook nightmares. The setting for each battle is suitably creepy, and the groaning sound you'll hear at the beginning of each wave will haunt your dreams. Okay, only if you're under the age of 12, but still... The details here from a visual perspective include easy-to-use menus that stay out of your way in the midst of the action, and equally easy-to-understand indicators that show how you're doing against the evil horde. There are some quirks, such as the lack of a visual indicator for the range of a unit BEFORE you select it to use in battle. Especially for games in this genre, planning by range is important. You learn the effective range of each unit with practice, but this still feels like an unnecessary handicap at best, or bad planning at worst.

Tower Defense has become a genre that feels a bit overdone and GRave Defense unfortunately does little to disabuse this notion. Wave after wave of enemies assault your position, and it's up to you to place turrets strategically and take them out. The theme of GRave Defense is original, but the gameplay is right out of the strategy playbook. Your choice of units changes from level to level, but there are generally three distinct types: Fast firing but weak, powerful but slow, and specialty turrets. The last category includes the expected turrets that slow down fast-moving units, plus some oddities like turrets that syphon money from downed units. You'll have to balance the cost of units with their ability to fend off ground and air attacks; not all turrets do both, you know. Three options are available in what's called Campaign Mode, and all of them have in common a finite amount of oncoming enemies you will have to defeat without losing your store of life points. Survival Mode offers a similar breakdown between Gold, Silver, and Bonus campaign levels, but there's no limit to how many enemies the game will throw at you. In this mode, it's all about how long you stay alive. There are points and awards to earn along the way, but you may not earn as many of them due to the crushing difficulty.

That's right, we said crushing. When you see the words "casual," what do you think? Since there are three other, higher, levels of difficulty here you'd be safe in assuming Casual difficulty basically plays itself. The alternatives include Normal, Hard, and Insane. In practice, Casual felt about like what we'd expect to find on Hard or Insane, which put a huge damper on fun. There are several levels toward the middle of the first campaign (Gold) where you find yourself limited to just a handful of units. Without a lot of money, the exact placement of a few expensive units defines how the rest of the level will play out. As it turns out, the level doesn't play out because you suffer catastrophic failure many times before getting it right. Again, playing on Hard difficulty I might expect this, but not on Casual. Even if all other elements of the game were outstanding, the unbalanced, cheap A.I. would be a huge derailer. There's always some opportunity to tune the game to be more playable, which definitely needs to happen.

Looking at how well the trial-and-error gameplay holds up from a control perspective, GRave Defense does a decent job in most respects. Placing units works well up to a point, but you can end up accidentally choosing a unit while you scroll through the overall list. If this happens, you can simply recycle the unit to get back some of the money you spent on it. The same controls are used to upgrade units, which of course comes at a cost. Upgrading is critical to making the most of a turret, but you face the constant challenge of wondering whether to place more turrets or upgrade the ones you have. Other than placing and upgrading units, there's very little to control in the game. Larger arenas do require that you swipe to view your emplacements and enemy movements, but there aren't a lot of menus or complex multi-touch gestures to hang you up at any point. We liked the simplicity, but there should have been much more time put into tuning the A.I. before this game hit the App Store. What could have been a fun set of Tower Defense levels became an exercise in frustration. Most of us love this genre because it offers more than one valid path to success. You can win with speed or brute force, as long as you learn your enemy's weakness and know how to read a level map. It's very hard to win anything in GRave Defense, and not for the right reasons.