The trick to get lots of money is buy LOTS of magnets then upgrade then to five. Just stay in one spot, use your bomb upgrades (you should also have a lot of those) and WIIIIINN!
actually ive found a game similar to this except much more complicated because the game will cheat you in any way possible by killing you
its fun i forget what its called but i no its on one more level.com
 "The Light Temple"){kind=icon}
 "Dibbles 3: Desert Despair"){kind=icon}
 "You Have To Burn The Rope"){kind=icon}
 "Ultimate Assassin 3: Level Pack"){kind=icon}
 "Upgrade Complete 2"){kind=icon}
 "Effing Worms 2"){kind=icon}
 "Zombie at the Gates"){kind=icon}
 "Papa's Pancakeria"){kind=icon}
 "Coinbox Hero"){kind=icon}
 "Epic Combo!"){kind=icon}
 "Psychout"){kind=icon}
 "WereBox 2"){kind=icon}