http://en.wikipedia.org/wiki/Sacrifice_%28computer_game%29
"Sacrifice is a video game published by Interplay Entertainment in 2000 for the Windows 98 platform. Developed by Shiny Entertainment, it is a real-time strategy game, featuring elements of action and other genres. Players control wizards who fight each other with spells and summoned creatures. Impressing reviewers with its graphics, Sacrifice was the first commercial video game to make full use of video graphics cards that can process transform, clipping, and lighting instructions. The game was ported to Mac OS 9.2 in 2001.
Unlike many of its contemporary real-time strategy games, Sacrifice places little emphasis on resource gathering and management. There is no system of workers; the players' wizards collect souls to summon creatures, and their mana—energy for casting spells—constantly regenerates. Players customize their attacks by choosing from spells and creatures aligned to five gods. To defeat an opponent, the player's wizard sacrifices a friendly unit at the opposing wizard's altar, thereby desecrating it and banishing the enemy wizard. Aside from a single-player campaign, Sacrifice offers a multiplayer mode, in which up to four players can play against each other over computer networks." - Wikapedia.
Okay, 4 words. THIS GAME IS AMAZING!! It's so fun and the graphics r incredible. And it's challenging, no matter how many times you play! With so many worlds and paths to chose from, it's an all-out test of brain-power and a lot of luck!

Srsly, click on the link and read about it. Once you start playing you'll never wanna stop!
My sacrifice series videos:
Sacrifice Game - The magnafryer level - Part 1: http://www.youtube.com/watch?v=IUrA4nWeEpI&feature=youtu.be
Sacrifice Game - The magnafryer level - Part 2: http://www.youtube.com/watch?v=SQ39oYpU0Ok&feature=youtu.be
Sacrifice Game - The magnafryer level - Part 3: http://www.youtube.com/watch?v=WhGsCoR32BQ&feature=plcp&context=C470e928VDvjVQa1PpcFPyvULTQgAk92QkKhbJaan0T75-4KfcBS0%3D