An alternative method which is most likely quite a bit easier can be found here:
Expanded guide, lots of good info:
(Note: A lot of these tips are courtesy of Phr4nk0 - major credit goes to him!)
- I recommend using the modifiers 'Time Press', 'Low Tech', and 'Legend'. You can probably swap one of these out if you would prefer to not have one of their effects removed, but these are usually seen as the easiest.
- The only thing you should upgrade is your jetpack. I upgraded it first after wave 3, and again after wave 6.
- ALWAYS be firing your weapons - you could even rubberband the triggers if you like. It is not uncommon for one of your projectiles fired as you were turning to hit a stray enemy. This is especially noticeably with the missiles (second jetpack upgrade).
- Holding LB makes the camera target the closest enemy. This is usually a hindrance when actually trying to shoot them, but is very helpful for finding an enemy and turning towards them (so let go of LB when you're aimed near them).
- Clicking both sticks and hitting a direction pulls off an aerial maneuver - hitting them backwards does a u-turn which can be very helpful.
- Never board a UFO. It's a waste of time and your jetpack is better.
- Basically it comes down to killing as fast as possible, and practice a lot, especially if you're like me and were never very good at flying in this game. At the start of most waves the UFOs come from the same spot every time, boost straight at them head on, fingers on the triggers, go for the non shielded ones if they're there, you'll damage a bunch of them, and later when you have missiles even kill one or two straight away. Hit the breaks and circle round and start following one. Try to get behind UFOs and just follow it untill it's dead, I found that once you damage a UFO it starts targeting you a lot more. (Direct credit to Phr4nk0)
- In wave 5, there is an Archon on a plateau. It will target your allied battleships with it's laser, which will decimate their health. ALWAYS go for it as soon as the wave starts - be careful as they can destroy you quickly as well. Shoot at the legs, make sure to boost past it then turn around so it's not always shooting at you. When all the legs are down you can board either the head or tail - the head is faster but more dangerous (be ready to dodge the laser with the left stick!), the tail is slower but safer.
- In Wave 7, there are only 3 enemy battleships. As always, be careful as their turret fire is deadly. You should have the magnetic missiles by now, which makes things easier. Stay back and take cover if needed. Destroy the first two ships (destroying both turrets takes out the ship), but leave the last one alive. Tail it from a distance and destroy it's mines as they pop up. You'll get extra points and will slowly raise your multiplier. When the wave is close to being over, quickly take out the ship for lots of points. (Credit to Phr4nk0)
- Wave 10 has 3 Archons, but if your ships are in good health, you can afford to take out the small ships first to raise your multiplier a bit. Be VERY cautious when fighting the Archons, especially if you do the finisher on their head - it's infuriating dying so close to the end when you're doing good (it happened to me!).
- The last tip isn't what you want to hear, but it's the truth - practice, practice, practice, then practice some more. Each kill, each wave, and each failure will make you better and better at this mission. Just keep trying and you'll become the Top Ace in no time