Tower Defense games fall under the category of Strategy Games and are peculiarly alluring. Their origin can be traced back to the arcade games of the 80ies. If you like mental sports, strategy and games of logic you may find Tower Defense games interesting. The mechanics are usually very simple but there are a lot of TD games out there that have created stories around the levels and a mythology around the purpose of the game. The goal is always the same: defend against an army of creatures or machines that the computer unleashes in usually defined paths. You have to destroy them as they are passing through, by placing stationary Towers to attack them, before they can reach the end of the path.

The TD Games that have been developed range from the classic ones that have no story or particularly complex graphics to modern ones that may have more complicated game-play and / or stories at the background. Some have really fancy and lively graphics while others concentrate on creating somewhat monotonous graphics with or without complex towers.
The first TD game I ever played was Flash TD – Warcraft 3. It was created by David Scott in 2007 and had been played 140 million times within a year! This was probably the game that mostly influenced how all subsequent modern TD games operate in their core mechanics. It is “THE” TD game and the one that got me addicted to this genre. Visiting the official page right now I can’t find the Warcraft 3 map. But I believe that the Warcraft map preceded the maps that are online right now here: Flash Element TD. There are still some places you can find the Warcraft map like this one: newgrounds.com
I have played most (if not all) major TD games that were created afterwards. Some of them were not to my liking but there are many which I have played consistently and few that are simply genius.
The games that mostly caught my attention were:
Bloons TD 5 was the first game that was not only notably good but had the complex design to keep one busy for a long time. Bloons TD 4 came out in 2009 and sold over 1 million copies on iOS. From Bloons TD 5 I went to Monkey City which is probably the biggest and best TD game at the moment out there. (Detailed reviews for each game to follow in separate articles.)
Defender’s Quest is an unusual but extremely intriguing TD game due to its story-line. I found the dialogues and the texts incredibly well written. The plot is quite occult, mystical and manages to create suspense. It is very rare to find good pieces of writing and compelling stories in computer games. The art of the game (graphics) is also very polished. The actual game mechanics does not require extremely brilliant strategic abilities, it does not pose extreme challenges like Bloons Monkey City and Bloons TD 5 have. Defender’s Quest also will not keep you busy for months to years like Monkey City does. Because Monkey City has a lot of farming elements due to the vast amount of tiles one has to beat. On the other hand, Defender’s Quest is extremely entertaining and has a more artistic value like a true computer game.
If you want to play Tower Defense I would recommend to start by playing the classic one (Flash Element TD). After beating that you will have the skills to play any TD game you want. It’s like the “father” of all TD. The next game I’d recommend is Monkey City. The reason to that is because Bloons 5 has a slight different logic and the towers there work a bit differently. To avoid the confusion of readjusting to the improved and much expanded version of Monkey City, I recommend starting directly with Monkey City.
Monkey City has quite fancy graphics and its all about popping balloons that come into the map. The towers are among others.. monkeys that have special abilities, like wizards, bombers, pilots etc. The balloons start as simple one-layered red bloons and continue from there with multiple layered bloons, rainbow colored self-regenerating bloons, to ceramic and lead ones. Then follow the various big flying zeppelins. In order to unlock advanced towers you need to build research centers and power centers in your town to discover them. As you keep beating tiles, your city expands and you get more space to build more power supply buildings, more farms (for in game money) and more defensive towers. There is also a PVP option in that game but not many use it.
TD Games you have to complete at least once are: Defender’s Quest, Kingdom Rush, Kingdom Rush Frontier, Gemcraft and Bubble Tanks TD. One of the best places to play TD Games online is Kongegate.com. Here is a list with all TD Games on that site.