Comparisons to Metal Slug aren't without merit, but CT Special Forces carves its own identity thanks to the intricacy of its levels.
CT Special Forces is an example of an action game that does a lot with a little. You can run, jump, shoot, and switch between a few different weapons, but with the exception of a few minigames here and there, that's the extent of the abilities the game gives you. It's the use of these abilities within the context of the game's cleverly designed levels that makes CT Special Forces interesting.
People have compared it to SNK's Metal Slug games, and while that comparison is a bit optimistic, it isn't completely off the mark. You play the role of an elite commando sent to fight alone against a terrorist army. The backgrounds aren't as intricate or as inspired as those in Metal Slug, but the characters and vehicles in both games share a common look. That's not easy to quantify in words, but if you compare screenshots of Metal Slug and CT Special Forces, you'll notice the similarities. The style and quality of animation is the strongest link between the two games. When you or the enemy fire weapons, you can see the accompanying muzzle flash and watch the spent shell casings eject from the chamber. When you stand still, your character pulls out his binoculars and acts like he's checking out the terrain ahead. And when a terrorist dies, he doesn't just disappear--he falls to the ground in a dusty heap. The soundtrack seems vaguely militaristic, but here, too, the game takes a page from Metal Slug and hypes up its audio with a variety of voice sound effects. Whenever you shoot a terrorist or get shot yourself, you'll hear one of a number of different "oofs" and "owws." Even the attack setup seems borrowed from Metal Slug--your main weapons are a pistol, a machine gun, and grenades. A few levels in, you'll be able to use other weapons such as a flamethrower and rocket launcher.
Copycatting Metal Slug isn't necessarily a bad thing, and to the developers' credit, the levels in CT Special Forces give this game its own distinct identity. There are ledges to jump across, tiny hills to hide behind, and trenches in which to duck. The enemies are wearing body armor, which means that they usually take three or four shots to kill, so you can't just run through them with guns ablaze and assume that they'll die before you can squeeze a shot off. In some cases, the best strategy is to duck beneath a pile of rubble and fire your shots while the enemies are reloading. In other instances, like against jeeps and mortars, your best bet is to get right next to them so that the gunfire passes safely behind you. There aren't that many distinct enemies--perhaps 10 or so in total--but their placement in the levels, along with a few color palette changes, does a good job of making you think that you're facing an army of hundreds of different commandos.
CT Special Forces is also longer and more drawn out than your typical arcade-themed action game. The levels rarely take you on a straight route to the boss. You'll need to climb rocks to reach higher ground and backtrack in some instances just to move ahead. Once in a while, you'll come across a guard post blocking your path or a group of terrorists shooting at you from a foxhole, both of which you'll need to stop and deal with. In some levels, there are giant mazelike bunkers that you need to go into and clear out before you can move on to the next section of the stage. And just for good measure, the game throws a minigame task at you in each of its levels. There are three such tasks that occur multiple times throughout the game: In one of them, you have to open your character's parachute when a pair of indicators line up; in another, the view shifts behind the crosshairs of a rifle, and you need to snipe at all of the terrorists in the distance before their bullets completely drain your health. The last minigame is a top-view, vertically scrolling shooter that places you into the cockpit of an attack helicopter. The goal is to make it to the end while shooting at other helicopters and dropping bombs on tanks and missile launchers. These helicopter stages are actually better than many of the stand-alone shoot-'em-ups that are currently available for the Game Boy Advance.
Like many other character-based shoot-'em-ups, the main problems with CT Special Forces are that it's repetitive and that it's over too quickly. Killing the same carbon-copied soldiers gets old after a while, no matter how many trenches are put in your way or how many different weapons you get to use. Also, while the game's levels are huge, there are still merely 12 of them. Most players should be able to complete their first run through the game in a day or so. If you enjoy action games in the style of Metal Slug, however, you've likely already accepted that these kinds of concerns tend to come with the territory.