That has to be some sort of record...
Level 4 w/Titi
Over 212000'
1 Cannon, 2 Berserkers, 2 Mechanical Commandos, 3 Power Smashes...
Enough exp to go up to level 8.
agree with palmtreestalker: if you want the medium badge without too much difficulty, just build a long maze with pellet towers and upgrade them 1 by 1. The 100 Level Challenge Maze here works good: http://www.neatorama.com/2007/04/14/desktop-tower-defense-strategies/
@chrisrulez For the 16 Goose achievement, my advice would be to NOT buy the homing beacon upgrade until after you have it. You'll pick up less stray geese by accident this way.
@rrwizard - be very fast, take as many of the 8's as quickly as possible and take out any red base that has less than 10 in it. Long story short, take out anything weak and don't worry about casualties. Same thing applies to all other levels.
Pretty easy game so long as you move fast, I beat every level first try. Anyone else wonder why the achievement is for level 14 and not the final level, 15?
Thanks to Cfsa for the hints, I was able to finish with 39 weeks remaining. Elite Skeletons are still hella hard to beat though, lots of luck required.