• Developer: Hidden Path Entertainment
• Release Date: December 8, 2008
• Platforms: Xbox 360, PC

Defense Grid: The Awakening might be one of the older entries on this list, but it’s still one of the stronger games to come out of the tower defense genre in the last 20 years. There’s a main storyline you can play through that will last you up to eight hours, but as with most games in the genre, there’s much more replayability beyond that.

When you start Defense Grid: The Awakening, you’ll begin on some fairly easy levels that challenge your basic ability to set defenses. As you progress, you’ll unlock new tower upgrades and types, with each tower having three distinct capability levels. The different towers all have strengths and weaknesses and some might be strong on one map while weak on another. Speaking of maps, there are 20 unique ones in Defense Grid: The Awakening, with more available through a paid map pack. The maps can spawn a total of 15 different enemies that become stronger the more you play.

The enemy variation and the amount of them that come into play often make every round feel like it’s coming down right to the wire. While your towers might not get overwhelmed at the start of a round, stronger enemies in larger numbers show up as the round goes on and can overthrow your entire strategy.

While Defense Grid: The Awakening is an older game, it still captures the magic of what a tower defense game is supposed to be. Pair that with graphics that look straight out of Halo and you have a game well worth checking out.