Defending six cities in City Shield, Games by Zaweba

Six cities sit at the bottom of the screen in City Shield, and missiles are raining down on them. The only thing between them and the ground is you, a few bases and a limited supply of interceptors. You click where an interceptor should burst, and the blast destroys anything flying through it. It's an 8-bit game in the 64K home computer style, on the Retro arcade shelf of Games by Zaweba, and it's as much about planning your shots as it is about speed.

How firing works

With the mouse, aim and click. The nearest base that still has rounds left fires an interceptor to that spot, where it bursts. On the keyboard, the arrows move your aim, Space fires from the nearest base, and 1, 2 and 3 fire from the left, centre and right bases.

That choice between the nearest base and a named one is useful. The nearest base gets a round there soonest, but if it's running low you may want to save it, and the number keys let you choose which base spends the round.

Making each blast count

Blasts destroy any missile or bomber that flies through them, and they can set off more blasts. That's the key to playing well. You don't have to hit a missile dead on; you have to put a burst where it will be when the burst happens. Aiming a little ahead of a falling missile, rather than at it, gives the interceptor time to arrive.

Where missiles are bunched together or crossing, a single well-placed burst can catch several, and the chain of blasts that follows can catch more. Waiting a moment for two trails to come close can save you a round, as long as you don't wait so long that they're past the point you can reach.

Ten rounds a wave

Each base has ten rounds a wave. Spray them about and you'll run dry before the wave is over, leaving a city with nothing to protect it. Spending rounds carefully is the real skill of City Shield. One burst that takes out three missiles is worth far more than three hurried shots that each take out one.

Keep an eye on which base is running low. If one side of the screen has used most of its rounds, the others have to cover it, and the number keys help you spread the load across the three bases.

Scoring and bonus cities

At the end of a wave you get a bonus for the cities still standing and for rounds left over. That means saving ammunition pays twice: it protects you, and it scores. A bonus city arrives every 10,000 points, which can make up for one lost earlier in the game, so a strong wave can bring you back from a bad one.

As waves go by, the temptation is to fire more and think less. It usually works the other way round. The calmer you are about leading your shots, the fewer rounds you spend and the bigger the end of wave bonus.

Pausing, full screen and best scores

Games by Zaweba keeps your best score and your plays on your PC, and shows your best alongside your score when the game ends. Esc pauses during a wave if you need a moment, F11 makes it full screen, which gives you a bigger sky to watch, and the title card and F1 explain the keys, including the three base numbers.

The trails, the bursts and the sounds are all made in code, so it runs offline with nothing to download. Lead your shots, let one blast set off the next, and treat every round as precious.