Metal Slug 3 is a good side-scrolling shooter, but the finicky controls in the iOS version ruin the experience
The main reason Metal Slug 3 for iOS devices cannot be recommended is the controls. There are a few games in the App Store that were originally designed and released for consoles and handhelds that were meant to be played with traditional controls (buttons) that work well: the recently released Mutant Mudds and Shantae: Risky's Revenge, among others.
Metal Slug 3 is a fast-paced, challenging shooter where a plethora of enemies and debris flood the screen, and your character dies in one hit. Using the on-screen analog stick to both aim diagonally and move forward or backward at the same time is frustrating and almost impossible to do with any sort of precision. Alternate routes can be taken in certain stages; stage one contains a submarine route, but instead of being an enjoyable set piece, the controlling of the submarine punishes the player for choosing a different path.
It's too bad that the controls completely ruin the experience, because Metal Slug 3 is a fun romp with a good sense of humor and cool power-ups. In the second stage, when you are bitten by a zombie, you will turn into one. As a zombie you can attack by spewing a stream of toxic blood out of your mouth to eliminate anything on one side of the screen. Lots of guns and bombs can be retrieved by rescuing hostages, and these fun-to-use weapons are especially useful against the terrifyingly enormous bosses.
Though you can choose between four different difficulties, even normal mode will prove to be too much of a hassle due to the controls. Local blue-tooth multiplayer can be utilized for co-op, but wi-fi capabilities are absent. There is a session save feature in which you can save the recordings of your play-throughs, though it probably will not be utilized much. Metal Slug 3 has a couple of nice features, but it's pretty barren overall. This was originally released as an arcade game, after all, so it naturally was not meant to be very deep. And for under a dollar in the App Store, Metal Slug 3 would be highly recommended if not for its fatal flaw.
Apparently, there are those who can muster the controls and find an enjoyable experience in Metal Slug 3 for iOS, but anyone who gives it a try cannot say that this is how it was meant to be played.