I played a lot of tower defence games in Warcraft 3. But Orcs must die sets a new level in this genre.
Combining a 3rd person action game with tower defence, it created the ultimate action survival game.
Set in a fictional fantasy universe, you have to defend humanity against hordes of orcs from another dimension. For that, they built big fortress' around the portals, you have to defend.
For that, you not only have weapons and spells, but a big arsenal of traps and mechanical defend systems, from ordinary spike traps to big swinging clubs, burning pits and big brutal mechanical grinders.
Every level is made of one or several floors with one or several directions the enemys can spawn. You have to defend the rifts to the normal world, so the orcs dont conquer it.
Using the right collection of traps, wisly using your abilitys and being a tactical genius desides about victory and defeat. The game doesnt take you lightly. With the first levels being easily understandable and mostly fast to solve, some maps are difficult beyond everything encountered before. Some maps need tricks you have to find out all by yourself, some just need you to be fast like sonic, defending two rifts at once.
Having a small storyline, mostly living from comedy, the campaign is really fun to play. After one playthrough you unlock another difficulty, that is a serious challenge (and was a real pain for me).
It isnt a real game for casual players, but a good game, for tacticans, that not only want to think but slay their way through their enemys.