"Metal Gear Solid 4" question...?

May be...

So what's up with the geckos? They are unmanned robots, but they spurt blood and their legs look biological when Raiden slices them. Are they robots, or cyborgs, or what?

Bio mechanical I guess.

biomechanical. which makes them more fast, the ability to jump so high and so on. the blood sort of mimics the way our body handles the blood. the blood basically supplies it with nutrients (if you want to call it that) to the rest of the gecko's parts to keep it up and running

They have organic legs ( which is why they're so fast and agile) and mechanical parts, so they're bio mechanical

BioMechanical.