the thing about making games that have immortalities and killer is that it varies with everyone so with some people it works with others it doesnt.I think it may just be that your not using phun beta 5.
Nice, I really like the idea. the only problem is as you said the water.but it would also be nice if you controlled just a person with geometry actions and then when he gets into a car he can move inside the car to move the car. keep it up