Earth Defense Force: Insect Armageddon

Upon beating the game for the first time, you will unlock a new game mode called campaign remix. In this mode, the game spawns almost all types of enemies in a given level instead of just the ones you see in the normal capaign. Although the spawns seem some what random, the best place I found to grind this out is on chapter 1, part 4: "Ditch Slap". Once you clear out the drainage ditch, you will have to plant explosives on a blockade in order to progress. Then you will enter a tunnel with three anthills. On campaign remix, you have about a 50/50 chance that the game will spawn spider nests instead of anthills. If you get anthills just restart the level. Using this method took me around 1 1/2 hors to grind out my remaining 7000 kills.

Using the campaign remix mentioned above you can also do mission 1-2 "firebase clyde" and get spiders instead of ants from the hills if you want to do a level that is not quite as long and difficult as ditchslap. The 50/50 still applies to whether you get ants or spiders.

As with always, don't farm solely for the enemies, tie it together with something else.

My suggestion:
Tie this achievement as well as the 5000 ticks and getting enough cash to buy everything together with trying to farm all the weapons.

For this, you need to have beaten the game at least once (on normal, for example) and leveled one of your armours to Rank 8, thus having gotten the Pesticide weapon of that class.

Now, you start up either 3-2 or 3-5 in remix mode and inferno difficulty. There will be a ton of spiders and bombers, netting you about 8-12 weapons each time, and a couple of dozen kills in each section - and your blast will wipe them out pretty much in one go.

Each run takes about... 5-10 minutes, depending on your tactics and skill of not blasting yourself up. It is highly recommended to finish the levels for the needed money, too. You'll make about 25k in 3-2 and something in those lines in 3-5.

If you find 3-5 too hard, 3-2 is really easy to pull off and has no real tricky part if you always keep distance to everything.


Alternative Tie-in with 10,000 Survival kills + 500 Waves.

Take Marooned, the second wave has about 26 spiders in it - the third one has gun-ships and wasps.

You can also combine both. getting my necessary 7000 kills ended me up with about 4000 ants kills, 1000 spider kills and about 2000 gunships on that map, as well as about 100 rounds..