You need to beat 20,000 points for this achievement. Find Liberator on the first page and press
to change the game options. Make sure you have Starting Lives set to 8, Bonus Life At 15,000, and Difficulty set to Easy.
When you start the game, you can cycle through the starting level by pressing
. If you are trying to earn this quickly and want to skip levels I would suggest starting at level 10. Otherwise, you can just start from the beginning and you should have enough points by Level 6.
= Fire
= Shield
At the start of each level, quickly take out the planet's bases (red blinking squares). If missiles get too close and you can't fire upon them in time, use you shield. Be careful of the UFO's quick attack as your shields won't protect you from it.