Space Invaders Extreme

For this achievement you have to beat all 5 levels of the "Arcade mode".

Here are some tips to make this much easier:
- Set your lives to 5 in the "settings".
- Hit 4 enemies of the same colour. This will drop a powerup to upgrade your weapon. Blue, green and red enemies give you more firepower. Grey enemies give you a shield.
- You can pause the expiration time of your upgrade by holding .
- Hit another 4 enemies of the same colour (for example 4 red and 4 blue enemies). This will spawn a special UFO. Shoot it to start a challenge. Completing it gives you fevertime what results to a heavy firepower upgrade (can not be paused).
- Shoot the special UFOs (they have a black line/ring in the middle) to trigger a bonus event like a roulette. This awards you with great bonuses.


Important tip if you started the "Arcade mode" with the standard amount of lives and got stuck in the later levels:
Normally you have to select "New game" to let this change take affect. But there is a workaround without losing your progress:
- Change the lives to 5.
- Move back to "Arcade" and choose "stage select"
- Start a level that you have already done.
- Hit and leave the level.
- Exit the "Stage select" screen and choose "Arcade" again.
- Now resume your game and lose all of your lives by dying.
- Now when you retry the level you will notice that you have finally 5 lives.


I hope these tips will help you.
If you have questions or improvements to this guide let me know in the comment section.