For various reasons (mainly console availability) the first Resident Evil game I played was Resident Evil 2. I distinctly remember being dropped off in a zombie-infested Raccoon City and trying to blast my way to the police station and safety. As RE fans will be well aware that was an horrifically bad strategy. You just couldn't play a Resident Evil game that way – there simply wasn't enough ammo to blast away the zombie hoards, you were going to run out of bullets and the zombies were going to have a delicious snack. After figuring out how to actually proceed in the game, I was talking to a friend about it and he concurred, Resident Evil games (at least those early ones) asked that you use your ammunition wisely; they asked that you only kill when necessary. That is what made those early Resident Evil games great – the brand of survival horror that they offered required some skill and thought, not just the ability to aim and fire.
Current Resident Evil titles have been far more action oriented and far less scary affairs. While there is still the ability to run out of ammunition, it isn't as huge a concern as it once was. The Mercenaries minigames which have popped up in the more recent titles only offer more ammunition, not less. The idea behind Mercenaries is simple – eliminate as many baddies as you can in a set amount of time. Now we have Resident Evil: The Mercenaries 3D which takes the minigames and tries to make a full title out of it.
Capcom has both succeeded and failed here. They have succeeded in that they have made a full game out of it, you can tell as much because they've packaged it and put it for sale as full title. They have failed in that it's not a very good game; it isn't one that will bring new players into the fold nor will it enthrall RE traditionalists. If there are areas you love from Resident Evil 4 and Resident Evil 5 you can revisit them here and they do look pretty good, but that's about it. The goals are generally pretty simple in the title – kill baddies before they kill you, and kill enough of them so that you're allowed to advance to the next stage.