I don't understand the praise this game got from the people back then. This game is not enjoyable at all. I enjoy or at least appreciate old school point-and-click, such as Beneath a Steel Sky, or I Have no Mouth and I must Scream, etc. But this "game", Syberia, is a complete backward from older point-and-click games.
Tower Defense is not usually my favorite, but this game is an exception. It has a simple but quite nice story where there's an alien invasion and you control the alien trying to convert earth. Not only that you build towers and watch, you can roam the map to attack enemy (human) creeps. You can even alter their path by strategically placing the towers. Some buildings are also destructible and will affect the enemy path as well. The control is very nice and smooth. There are 2 types of enemy units, ground and air, with various behaviors and strengths and weaknesses. Some levels have distinct final bosses. There's also a skill / upgrade tree for your base and ship.
If you enjoy casual point and click such as Beneath a Steel you would probably like this game, just don't expect too much. The perpetrator is easily guessed in the middle, so there is no element of surprise in the end. But it's still quite enjoyable. Disclaimer: I received the game for free