Why dont you try the samples, or the tutorial? Just a suggestion.

I dont think that 'level_load("small.x");' can work. At least there is not such file as "small.x". A valid level format would be "small.hmp" or "world.wmb" but no ".x".

The "small.hmp" is a terrain file and that must exist on your PC and if it does not exist it can not be loaded and thats why you get a black screen.