RAIDEN FIGHTERS ACES

*Final edit!!*
Made a commented walk-through:

I earned this a long time ago. I was once 1st ranked on the leaderboards with a score somewhere around 138mil. It is possible to get 100mil on Raiden Fighters 2, but it is incredibly difficult to do so, and I don't recommend the trouble, so focus on Raiden Fighters Jet.

You will notice that Raiden Fighters Jet is unique in that you skip stages depending on your performance. You might think that by playing the game on "Full Run" will earn you more points, however you won't. Every time you complete a stage, you earn a performance bonus. You won't earn the performance bonus on "Full Run" mode, making it a lot harder to reach 100mil.

I've reached 100mil several times before the ALL3 bonus you get for beating the game. The key to doing this is to get the X-Medals to appear on the first simulation level. After that, just focus on not dropping any medals.

You can make mistakes. The first time I got 100mil I died on Simulation Level 30. You also don't need to shoot down every enemy. Ignore the small planes, and focus on the big enemies that give you Quickshot bonus, or Destroyed At a Time. If you get enough of these consecutively, you get a temporary multiplier that goes up to x9. Discovering Fairies and Miclus also add to that multiplier. The longer you maintain the x9 multiplier, the more points you'll get on the performance bonus. Killing Fairies will decrease your performance bonus, so don't shoot them.

If you are not using the Judge Spear Slave or Ixon Slave, then start doing so as these ships are the fastest, and most destructive out of all the others. The difference in speed between the Judge Spear and the Ixon isn't that big. It all depends on which Bomb you rather have. I personally prefer the Judge Spear's because it keeps you covered for a longer period of time, and this really helps for the later stages.

Don't be afraid of using Bombs. It's better to drop a Bomb than to lose performance bonus. You will lose a big chunk of the bonus if you die, so don't. This isn't like Raiden II, III or IV where unused Bombs give you a bonus. Bombs are simply a safety net on this game. Fairies drop them if you wait 3 seconds after discovering them. Sometimes it's not worth the wait though.

If you are connected to XBL, make sure to play only on Xbox Live, or training mode only. This will force you to play the game without using continues. When you go on training mode, make sure you can beat the stage 5 times in a row without dying before doing the actual run. This will help you memorize boss patterns, and the location of the Miclus/Fairies. You should know where to be at all times.

Don't stress about bonus points. Bonus points are given when the enemy bullets rub against the wings of your ship. You can get insane amounts of points by deliberately grinding the bullets, but it requires a lot of skill and practice. I suggest you try to boost your score by grinding bullets once you reached 100mil. You can easily reach 100mil without bullet grind.

Another tip I can give you is to go to the video settings, and change the frame rate from 60fps (default) to 54fps True. It will make the game 10% slower making it easier to dodge bullets. You can also change the graphics to "bland" if you find it difficult to distinguish enemy fire and the background.

I don't have a youtube video, but you can review my replay on the leaderboards.

Edit: I mention that Bombs are "simply a safety net" however they are not. You can also use them to get Quickshots, Destroyed at a Time, etc. Bombs played a bigger role on Raiden Fighters (1) in terms of getting points. For example: in stage 1 before the boss battle, you can drop a bomb on the houses to protect them from enemy fire. You won't see this in Raiden Fighters Jet. But there will be some situations where dropping a Bomb is the only way to get a Quickshot or a Destroyed at a Time.

2015 Edit: Raiden Fighters Aces leaderboards reset your score, and delete your replay after a year. That being said, my original 1mil replay is not on the leaderboards anymore. Hopefully I'll get a youtube version going and post it here (I don't have the equipment to record, so...). For now, you can look at the current leaderboard and see the replay of anyone who has broken the 1mil barrier.

Further to the excellent guide by MexiSerge

Below is my video run of me unlocking the achievement. (On the Japanese version, but the game is the same)

I select the Slave ship for the speed and power.

I make a few mistakes early on, notably I destroy the first tank with the fairy on Stage 1 too soon. (I personally never bother with that fairy, gives me very little extra bonus for the trouble it is to save her.)

The start of Stage 2 I miss the last train carriage, losing out on the DX bonus.

I lose 4-5 million from what I could gain, so there is room for improvement.

Hopefully the video can help people with general tactics otherwise.