minigolf - display anything 3d
QBASIC 211 bytes

SCREEN 13
WINDOW(-160,-100)-(159,99)
FOR x=0TO 63
 PALETTE x,x*65793
NEXT
FOR i=16TO-16STEP-.1
 FOR j=16TO-16STEP-.05
  s=SQR(i*i/2+j*j/2)
  PSET(i*10,j*5+17.32*COS(s)),18.2*(COS(s)-SIN(s)*j/s)+31+RND
 NEXT
NEXT


The color for each pixel is chosen by adding the z value on the curve with the partial derivative with respect to y, generating a 'fake' lighting effect. The added random value helps to smooth the borders between regions. Produces something similar to the following: