With newer enemies (from generic to final bosses) and more original level designs, Metal Slug 5 is a clear improvement over the previous entry in the series. But it's still a near impossible game to survive through with all of your stats intact.
This time the levels include jungles, deserts and factories. It doesn't sound like anything new but at least their isn't the heavy sense of Deja Vu that plagued Metal Slug 4.
Though I still have no idea why your character gets a life bar when the tiniest contact with a bullet kills him/her. And please, give us some new playable characters next time, or at least change their clothing.
A fun shooter nonetheless, but it does seem a little shorter than the others.