Curse you! Curse you for making me lose sleep! :mad:
On my 3rd try, I finally figured it out.
11,601 upon beating lvl 39. Rank 830.
My tip: You get 5 “pieces of wood” over the course of the game. If you want it to be easy, I recommend this order:
-Fire
-Interest
-Interest
-Water
-Earth (for rockets)
8000 pts is actually pretty good. The best that I’ve managed to do is only about 14k. The key to the really high scores, as I understand it, is interest.
Buy only after each level, after you’ve gotten your interest payment. Use wood to keep increasing your interest rate. Only have the bare minimum towers necessary to finish the level. Don’t be afraid of leaking creeps, especially the bosses, since it might cost you more to build the towers necessary to take out the boss than you’d get from killing him the first time around. If you’re going to sell towers to buy new ones, sell them during the level so that you get the interest on the sale price.
I’m a huge fan of the arrow towers- since they can hit everything, they’re actually a good default tower. It’s possible to kill the first level with one, properly placed, un-upgraded arrow tower, for example.
Randy, I don’t believe you need the rockets at all, I scored well over 12,000 bonus points on interest alone in the last two rounds. Interest is definately the key IMNSHO 
. You can see it add up really quickly. After lvl 7 I use nothing but fire towers and the rest of the wood is for interest only. Interest cannot be stressed strongly enough if you are after the high scores.
From my rough notes.
lvl 1, 1 Canon
lvl 2, 4 Canons
lvl 3, 6 Canons
lvl 4, 8 Canons
lvl 5, 8 Canons
lvl 6, 12 Canons
lvl 7, 12 Canons. (Selling all canons before the end of the lvl to earn interest After lvl 7, 219 Gold)
lvl 8, 1 Fire Tower
lvl 9 & 10, 2 Fire Towers
lvl 11 & 12, 3 FT’s
lvl 13 to 17, 4 FT’s (Four FT’s cover all the map if placed correctly)(After lvl 15, 556 Gold)
lvl 18 5 FT’s
lvl 19 & 20, 6 FT’s
lvl 21, 7 FT’s
lvl 22, 13 FT’s (After lvl 22, 1413 Gold)
lvl 23 to 26, 17 FT’s
lvl 27 to 30, 18 FT’s (After lvl 29, 5,672 Gold)
lvl 31, 20 FT’s
lvl 32, 28 FT’s
lvl 33 to 35, 36 FT’s (At lvl 33, Upgraded 6 Towers, After lvl 33, 12,456 Gold)
lvl 36 to 38, 48 FT’s (Before lvl 36 I double upgraded 12 Towers. After lvl 36, Gold 24,228, Score 28,678)(lvl 38 double upgrade to 6 Towers)
lvl 39 (all hell broke lose note taking went out the window)
Final score: 57,318 Gold, 57793 Points, Rank 263.
There is plenty of tweaking that can be done to the above, but if I try again right now my wife will kill me, I’m supposed to be laying a new floor at the moment. Damn this stupid game, will some body start that pit thread already. 
Agreed, just becareful the leak doesn’t become a haemorrhage though. Oh did I happen to mention Interest, I can’t stress that enough if you want the high scores you need interest.
This is a good game.
I had 9000 something. I give more time later.