STRATEGY GAMES are rarely programmed to the same standard as arcade games but the new Quicksilva release, Gatecrasher, combines an elegant concept with slick graphics. In the game you must drop barrels - they look more like marbles on the screen - down a maze and attempt to fill nine boxes at the bottom of the screen. The maze contains a number of flip-flop baffles which deflect the barrels along different paths. Each time a barrel hits a flip-flop the flip-flop reverses, so that the next barrel will be sent in a different direction.
At later levels you must not only fill all the boxes but also arrange them in the correct order. Each one is numbered and dropping a barrel in a box will swop its number with the one to the right. Since you have only 20 barrels you must plan carefully to complete the task.
Gatecrasher is extremely challenging and a welcome break from alien-bashing.