This demo shows a relatively complete handling of level 24. I don't exploit every secret (alas, some remain a mystery to me), but I acquire enough goodies to destroy Tycho Brahe without ever being in real danger.

It's a long demo, so I won't give you a detailed blow-by-blow, but here are some things to note:

• Patience and persistence when dealing with the "minefish." I don't rush headlong into danger when chasing them, but I do track them down and eliminate them when I find them.
• Use 'em or lose 'em. This is the last level, so there's no reason to save your ordnance. I took this approach, in general, throughout the level, but it's particularly obvious in the Yellow room. Megas are useless against the boss, so I use most of my stock to make it easier to grab the red key. (Should have used even more.)
• Keeping the boss's attention. When engaging the boss, I fire at him with my Gauss, even though I know it's not hurting him. I do this to keep him facing me, so the 'Shakers I shoot at the wall behind him will hit their mark.
• There's more to the Red room. I end up dispatching the boss surprisingly quickly, so I don't reveal all the secrets in the Red room. See my L24Boss demo for more complete coverage.

Well, that's about it. I hope this demo helps you.