REDUCE LAG ON CHROME:I can see quite a few people complaining about lag in the below comments. The game started off fine for me, but got laggy near the end. I am using google chrome and if you type 'chrome://plugins/' without the apostrophes, you will get a list of all the plugin that are currently installed in your google chrome. I disabled all of them apart from: Google update, Adobe Flash player and Silverlight. After I did this, I have not experienced lag at all. Not even on the last two bonus stages. I am sure there are similar option on firefox as well as other web browers.
The tactic I used for getting the Kamikaze badge. You need to make sure the bottom ship is unlocked. I made sure to get my multiplier as high as possible in the bonus round by killing enemies with 'close range kills.' If you can get around 40x it will make it a LOT easier.
You need enough money to be able to level up your laser wingman to its maximum level and then purchase both kamikaze and commander, then keeping purchasing the gun of your choice (I chose classic) and you will most likely have enough money left to purchase a courtesy ship.
Now you are ready to start the survival mode. Try and collect as many purple power-ups as possible at the start and then once it starts getting a bit more hectic, concentrate on nothing but dodging bullets, as your wingman will do all the killing for you.
I hope this helps. Just persevere and it will pay off in the end :)
Titandrake;s comment was perfect. I actually ended up hitting a glitch where my velocity reached over 40 and it was too fast to collect the stars. I tried it a second time and worked perfectly.