Flash automatically handles garbage collecting, it shouldn't be leaking, especially that fast. Might be a different issue you're describing. Not much I can fix without further details and steps to reproduce, I've run the game regularly for hours on end while chatting etc. with no noticeable issues on my end at least. See the Bug Reports thread on the forums for more info on what info to include in reports.
Spoiler! Don't read down if you want the strategy to be spoiled,
The strategy that I used was- Go straight for the bases
Upgrading strategys- Get power first, then reloading, then cannons, start all over again. When those 3 were maxed, I got armor, health, armor health etc etc. That is how I beat the game.
 "Mutilate-a-Doll 2"){kind=icon}
 "SHIFT 2"){kind=icon}
 "Sacred Seasons MMORPG"){kind=icon}
 "Learn to Fly"){kind=icon}
 "There is no game"){kind=icon}
 "UPGRADE COMPLETE!"){kind=icon}
 "Deep"){kind=icon}
 "Platform Racing 2"){kind=icon}
 "TDP4 Team Battle"){kind=icon}
 "Doodle God"){kind=icon}
 "Easy Joe"){kind=icon}
 "ShellShock Live"){kind=icon}
 "Toss the Turtle"){kind=icon}
 "K.O.L.M."){kind=icon}
Flash automatically handles garbage collecting, it shouldn't be leaking, especially that fast. Might be a different issue you're describing. Not much I can fix without further details and steps to reproduce, I've run the game regularly for hours on end while chatting etc. with no noticeable issues on my end at least. See the Bug Reports thread on the forums for more info on what info to include in reports.