How do I stop slowdown?

Hi. Im making an FPS game but it goes really slow and sluggish on pretty much every computer. Any tips on cutting the fat so to speak and speeding it up? I've only got 3 skeletons, 1 guy, 4 buildings, 3 roads and a lever.

are you using things from the web gallery? some characters have their file sizes written underneath them in red or orange, showing that they are very big and need a lot of time to upload. if so, you may want to rethink your choice of character.

pingu