PlanetSide 2, Tribes Ascend, Natural Selection 2, Ravaged, Primal Carnage, Doom 3: BFE, Nexuiz, The Darkness II, Hawken, Gotham City Imposters...
So to get back to your point:
Considering the release date of all of these platformers it's far less saturated with a lot more variety between each game. Also, this isn't the only indie bundle in existence. There's a lot more variety in the other ones.
It comes down to the fact that it's simply more expensive to make a FPS and 3D games in general. Thus you see a lot less indie titles that try that unless it's an established company.