Nearly forgot about this one!
Not quite the 20 levels..more like 1.
Anyway here is a quit demo is for testing the mechanics.
<img src="https://dl.dropbox.com/u/22173473/splashimage.jpg" border="0">
1, Right Mouse (KEEP PRESSED) to activate scope/zoom
2, Left Mouse to Fire
3, Shoot the gaurds and barrels
You can only shoot when ZOOMED IN (its not a fault!)
Should get a decent frame-rate on Chrome