Cursed Treasure
This is the flash-version of the Dungeon Keeper. You are the "evil warlord" who stores treasure in his/her fortress, and the "good adventurers" come and try to steal it.
The gameplay was changed to a Tower Defense mechanics.
It is very easy to use, and has more then basic graphic.
The gameplay is good, sadly the concept behind the game ruins the experience. I mean there are no achievements for starter. That was although inserted in the expansion pack (Cursed Treasure Level Pack), but that ... thing suffers from boring maps.
What the original lacks beside the achievement system is the challenge overall. I mean it'd be challenging and tough to think out a strategy IF you wouldn't be able to level up infinitly (at least until maxing out all skills). Dang, that way is what is even encouraged by the developers (from all forums of the game all "do it in lowest level" efficiency comments were removed, and a "max everything playthrough" is provided instead).
Anyway, just to see if you can achieve "Briliant" score for all level it worth trying, although the skill-developement for that seems pretty streightforward. To be able to do the first 5 levels you need maximum pool of mana. For the 6-10 levels you need cheapest + strongest meteor spell. Seems that a highly buffed damage-tower (what means either the last skill from green or red) is also a must (so it'll be red).
For 11th and 13th level you'll have to buy max. freezing + max. fear for blue towers. Without freeze you'll have absolutely no chance winning Briliant score for the "hard" maps.
For the remaining levels it seems you'll need more money and/or cheaper woodcutting spell.
It is rumored the very last boss is only defeatable if you have max. meteor and can supply to with mana from building red towers.
Well, that's my hints for you