Looks can be deceiving but if you were expecting something similar to Metal Slug...this is not it, you will be deceived. My first impression was, "Well this could be good" and hey, what do you know? It wasn't! Graphics are good, gameplay is glitchy, however. Controls need to me patched, because when you try to run backwards and shoot, your character will magically turn around and shoot, the other way! Not behind you but right in front of you! Also, the "joystick" will eventually get stuck. Move it diagonally and you might be stuck shooting into a corner. Furthermore, attempts to get it "unstuck" will be unsuccessful, you'll find it gets stuck in more ways than one.
Overall, if you're looking for Metal Slug then don't bother with this imitation. It may be free but if you spend money on the in-app purchases, you must be careful as there are others who claim your guns will change on their own accord. Sadly for the developer(s) I will not stay long enough to find out.