Desktop Tower Defense

[RandyWayne]

Here is one that is taking far far more time than it should be.  It's called Desktop Tower Defense.

http://www.handdrawngames.com/DesktopTD/

Once you play a few (very) quick test games you will understand what is going on.  Your mission is to place gun turrets within the arena and keep creeps from traveling from one end to the next.  Once 20 (total) make it, the game is done.  You use gold to buy weapons and upgrade them as the game goes on.  So it is essentially a resource-management game.

[mini]

Here is another game like that one, only a lot easier.

http://hallpass.com/media/bloonstowerdefense.html

I made it to level 50 twice now.

[RandyWayne]

DTD does have some easier modes as well.
It is just that when it gets hard, it gets REALLY hard, if not impossible in some cases.