What you may not know is that in the last level (during the smash with Reflux) of the game there is an extra area that what I see is still unknown because well hidden.
Not being able to make a video I write a clear description to direct you in this secret area but beware I'm not talking about the Xowar secret area.
So reached this part of the smash with Reflux
take the power up of The Yellow Throttle Copter and immediately dive off the platform where previously you've fought against Reflux before it started to hover in the air.
You may notice that after several attempts at the bottom of the platform there is a small passage with a small entrance where you will find the latest gems in the game.
Obviously you risk several times to fall into the void, but if you can help right with the brief lenght of Copter you can in a few attempts to get to the secret area hidden under the platform.
I've discovered this secret coincidentally in 2003/04, but no one has ever talked about this secret passage, so I hope that my description has served to make known this additional secret area. Regards
