Hard Level 12 - Rabbit Hole

Waves: 38
Lives: 10
Cash: $24

The creeps take their time winding their way to the final destination. I found that setting up the towers early on was helpful, then it was a case of upgrading them at the right moments to keep on upping the ante. Well, I'm there. All levels of GeoDefense successfully completed without a single life lost. It only took three months. Good value for a £1.19 application. Bring on the next one - Swarm!

And here is a slightly different solution for Rich to try.

Hard Level 11 - Defy Expectations

Waves: 15
Lives: 10
Cash: $100

This took me many, many days to work out. You soon find that there is only one weapon which is effective throughout the game. However, despite many attempts, I just could not solve it. Then I tried putting in more Vortex Towers...

Hard Level 10 - Final Victory

Waves: 40
Lives: 10
Cash: $50

I used a nice mixture of colours to complete the task!

Hard Level 9 - Eternity

Waves:19
Lives: 10
Cash: $50

Everything seems fine for about the first seven levels, then something happens to the best-laid plans of mice and men... So get those Shock Towers into place!

Hard Level 8 - Resistance is Futile

Waves: 38
Lives: 5
Cash: $24

There are a LOT of waves on this one. At first the critters get wiped out quite quickly but get faster and faster. So you need to make strategic decisions fast as to which towers you upgrade and when.

Hard Level 7 - Final Push

Waves: 10
Lives: 10
Cash: $40

There is only one way to win. The critters come hard and fast, so that's the way you need to play. Just keep adding towers as quickly as you can. You'll get there.

Hard Level 6 - X Factor

Waves: 15
Lives: 10
Cash: $25

This took quite a few days and experiments with positioning and combinations of towers before I found a way to stop the critters breaking through. Unlike some levels I found that it was a good idea to use all types of tower, relying on their different abilities. For example, the laser towers have a long reach, but the blaster towers concentrate on nearby critters whch can be crucial in the final stages. Here's how I did it to keep all 10 lives intact.