If you've played Capcom's arcade classic Mercs, you have played Shock Trooper. And even though Shock Trooper does offer some new and innovative aspects, it doesn't gain enough momentum to get past the blatant rip off.
What Shock Troopers does well is give you a few players to choose from. There are a total eight characters, which is six more than are generally in over head shooters. Plus, you can go lone, or rotate between three, in a team mode. Plus it's two play goodness. All this, what could be wrong?
Well, from the first level on you know you've played this game before. Many of the levels are lifted straight out of Mercs, even some of the bosses are the same. There are quite a few levels, but it never quite hits the mark of some of the great arcade games of it's past. I'll take Mercs anyday.