Your mission is to watch the American Embassy and, if a terrorist passes the window, you shoot at him. Kill enough and you get promoted: but shoot a hostage, and demotion is immediate.
This is a simple reaction game where you move a cross-hair sight over windows and shoot. Terrorists appear in shirts of one certain colour - so don't shoot any other colour! But what makes life harder is that they change colour now and again and your best target suddenly becomes a hostage.
Every six shots you must move your gunsight to the armoury and fire at it to reload. This is usually when all the best targets appear. (It's as logical to shoot an armoury I suppose as it is to bomb fuel dumps in Scramble...)
As a subject for a game the morality is a little shaky. But leaving that aside, I also found it becoming tedious after a while. The only variety is in the shirt colour changing and the overall speeding up as you get more points.