|N version||1.2 and later|
Method 1 (Easy)
Jump to the exit switch on the left side. On the way back, take your time to pick up all of the gold. The key is to delay until the top laser drone passes below the platform right in the middle of the screen, since you will have to get to that platform later, and obviously you will not want the laser to fire at you when you try to reach that platform.
After getting the exit switch, get all the way to the right side and grab the door switch. Then walljump up the right side quickly, and make your way from platform to platform all the way to the middle platform. If the laser drone is low enough, you should be able to get there without much of a problem. You can now just leap to the top-right platform and exit, or you can proceed to the left side to get additional gold (though there may be a guided zap drone there).