Hi Nir,
       No manual for death racers. Basically, don't run out of fuel.
Pick up the blue fuel cans for more. The blue X's are an extra life.
Various weapons appear as the game progresses. Around
stage 4, an aircraft attack starts, you can pick up missiles to
stop these but need to fire them with the space bar!

No end..one of the ongoing games I'm afraid!
At the end of each level, you traverse a winding
road to a city, which has a black 'parking'(?) block at the
end. You need plenty of fuel for this.