The main strategies that I use when playing Bedlam 2 are as follows:

1. Collect as many gold bars as I can to get the Gold bonus.
2. Shoot as carefully as I can so that I can get the Sure-Shot bonus.
3. Shoot all meteors for the bonus and also for the extra ships and gold.
4. Shoot as many alien bombs and weapons as I can.
5. At the beginning of each level I major on shooting moving aliens and I don't get in a hurry so that when the multiplier appears I will have a target rich environment when I get a good multiplier.
6. I try to keep power extremed as much as possible. Especially near the end of the 4th wave of each planet so that I can make short work of the mothership.
7. A major strategy I use for massive quantities of extra points is to be on the "secret" spot when the ship blasts off after a wave is complete. When I have a wave down to one ship I go to the "spot" and sit there until I can shoot the last alien from where I am. That way I don't have to slide the ship over and hope I can get the right spot in time. If you haven't found this spot, it is [deleted by GZS].
8. The last strategy that allows me to get big point scores is to build up lots of extra ships. When I enter Mercury's mothership level I do not hurry in my effort to destroy her. I aim for the bombs. Once I am down to about 10 ships I start whittling her down so that I can get her on one shot. Then I shoot bombs until I only have 3 ships left.

My strategy ? ........mmm.
I'm not good at English. So, please permit bad writting.
I'm keep "Power Extreme" condition.
When the wave begun, I shoot, shoot, shoot and shoot, to get "Speed Kills Bonus".
(I don't care of "Gold Bar".)
I'm always waiting for "Multiplier".
But when it appears, I don't aim it immediately.
I shoot and shoot, until rest of aliens are one or two.
And then, shoot "Multiplier" (target x5 !!).
Then shoot aliens and finish the wave. I can get multiplied "Speed Kills Bonus".
If I could, I try to get Penetrators. With using it, I can special point.
Basically, I get a lot of points by multiplied "Speed Kills Bonus".
So, my high score is swayed by luck.
But always I score 1,300,000 certainly.