Dependencies: 

libfltk-dev
libglu1-mesa-dev
libgl1-mesa-dev

If you have all the required packages, make should succeed.

Hotkeys: 

F1 - see from train's POV
F2 - see from train looking backwards
F3 - see to right of train
F4 - see to left of train

Home        : Toggle complex trees / basic cones
PgUp/PgDown : Increase / Decrease number of slices in trees
=/-         : Increase / Decrease number of stacks in trees
w/s         : Move robot forward / backward
a/d         : Turn robot left / right
SPACE       : Jump robot!
Up/Down     : Accelerate / Deccelerate roller coaster

Hold left mouse button and drag to rotate view. 
Hold right mouse button and drag to move in the plane of the camera.
Hold both buttons and drag to zoom in/ out. 

Special thanks to kixor for use of obj parser code: 
http://www.kixor.net/dev/objloader/

Your obj parser seg faults for 2D texture coordinates, because strtok returns a 
NULL value the 3rd time it's called:-) Easy to fix.