Trying to artificially inject excitement into a tower defence game is a dangerous ploy. It should already be there in your design, a mix of escalation and tough positioning decisions pushing the player to think in new ways.
Adding new and contrary elements, as Colossal Games has done with Commando Jack, requires a deft touch, and some careful balancing. Unfortunately, the game never quite manages to get the balance right.
Tower commandYou play as Jack, who's been targeted by a race of aliens for annihilation. You need to build a run of turrets, guiding the alien scum through a maze of bullets and lasers, all the while keeping them trained in the sights of your not-so-secret weapon.
When you tap an icon in the bottom-left of the screen the view warps away from the traditional top-down tower defence angle into Jack's point of view. And Jack's looking down the barrel of a very large gun.
While your auto turrets pepper the waves of invaders with bullets, lasers, and goo that slows them down, you can blast them with your own weapon, cutting the invading army down to size in no time whatsoever.
There are a variety of different aliens to shoot at, all of whom have different weaknesses and vulnerabilities, so learning about your foe is an essential step on the road to victory.
Defensive errorYou'll kill aliens, and spend the money you get from that building new guns, and then spend the points you get for completing levels on buying ever more powerful machines of war.
The problem is, the levels aren't particularly interesting, and more often than not you'll just find yourself blasting away at the same spot as another stream of aliens stomp towards you.
And because your first-person shooting is an integral, and frankly dull, part of your defensive line, you can't fast-forward the waves like you would in a standard tower defence title.
Commando Jack tries to inject an urgency into the tower defence genre, but only manages to make it less exciting. There's less strategy, less clever ordinance, and - thanks to the underwhelming nature of the first-person blasting - a lot less fun.