Desktop Tower Defense: Perfect Job

There is a game that is damn popular, but not really treated as a piece of good game design, but merely a lucky case of good propaganda is HandDrawnGames Desktop Tower Defense. I like to review it because i believe that from a game designers pov (point of view) it is a clever masterpiece.

It probably isn’t the most innovative game out there, the original game concept of Tower Defense has already been popular among RTS mods since end of nineties (e.g. Starcraft), but lately got reincarnated into this very well acclaimed flash game. I would like to talk about what I think is special about the basic game concept of Tower Defense and especially about Desktop Tower Defense.

Three simple and basic but still important steps of good game design have been done right:

  • Vision as in inspiration (from existing games) and the one-line game idea it should boil down to.
  • Basics: from knowing your technology to basic game design rules, decissions and their results.
  • Improvements, that stand out from the crowd.

Basically I don’t want to describe how Tower Defense plays, as i believe everybody has played it already. And if not, just do so, its worth the experience.

This is what it looks like when a newbie loses his first time.


Tower Defense can be traced back to its roots, having clear influences from different RTS (real time strategy) games.
But it also has a direct ancestor: Rampart. In Rampart, the player builds a wall and places towers. After the building phase, the installation needs to be defended against incoming enemy waves. The basic strategy was handling damage per cost related to damage per time.

Interesting to see, is that while many people think Tower Defense is RTS, it actually differs from the other available RTS in that you not only have no moving units but also your enemies won’t damage your buildings (towers). Actually the game thus has a more positive, constructing, simulative character. a nature similar to Sim City, Settlers (”Serf City, Life is Feudal”) and godlike “decide, build, watch” games.

The main goal of real time games is the positive addiction that players feel. The full fun of the game comes from the fact, that you can experience your improvement as a player due to the short feedback loop. Tower defense has mainly 5 “levels” of addiction, each later one stacking on the lower levels or shelling the earlier ones like Russian Matryoshka dolls.

  • First of all, fighting yields money which you can use to build better towers and thus gain money faster.(level 1)
  • Then, you can build more towers creating a maze that slows enemies down giving you more money for more towers.(level 2)
  • With the “send next wave” button of Tower Defense you can send in more enemies faster.(level 3)
  • The instant you loose, level 4 allows you to start a new match in which you can get more enemies/towers/upgrades. (unexpectedly it doesn’t matter that much for the first 100 times that you need to start from scratch :)
  • Finally, the classic highscore list in which you can see if you upgraded / build well enough and show others how good you are is on level 5.

This is what it looks like when you think you’re playing well.


The designers of Desktop Tower Defense seem to know the basics and do them all right. The game features really short play cycles, on the level of enemy waves but also the full time a whole session takes. This is an very interesting point for me, on which I would like to talk about in more detail in a upcoming post.

Another good decision is to have everything on one screen, making it easier to understand and easier to oversee and control. It also accelerates the gameplay which in turn increases addiction.

The game mechanic is split in two generally very well working areas: one being spatial 2D, where you have to decide where to place towers in order to create an enemy-slowing maze, where to upgrade in order to get the best out of the tower ranges. The other working area is linear gain of “avatar experience”, a concept well known from RPGs. The experience gain gives the player new actions (more expensive towers), allowing a good learning curve and also prevents boredom. It also gives the positive feeling of re-using existing stuff, giving the player the impression it was right to do/chose the stuff. Players simply upgrade towers without moving them.

Another basic the game does right is how it deals with frustration. In a single player game there are typically 2 major frustration sources (from the player’s pov): either the game sucks or the player himself. Games should always try to make as much as possible clear to the player. And of course stay fair. So that a player that loses (not yet good enough) always has the feeling this is his own failure. Tower Defense here clearly has no point of frustration but the players strategy. The GUI is clear and the interaction works well, the player can sell towers that he thinks aren’t well-build and the appearing of enemies is happening as expected, wave after wave, without any shocking events (which is good for a game – in reality, enemies don’t come in nice little waves – but games should be careful about what parts of reality to simulate).

The manual of the game is really short and placed well below the game’s flash window. it is easy to read there, available at all time while playing without the need for any in-game interface and the easy structure makes it perfect for beginners to use it a few times while playing untill they understood everything. Additionally, I think it is also good that the game has no tutorial. I haven’t felt well with any tutorial of any game in the last 15 years. Even those I designed myself.

The look of objects (visually) is clear and understandable, everything has a character. It is not necessary to have high quality shining visuals, but to stick to “style”. The game (as do many flash games) has good animations (including particle effects), which fit to the events/actions that happen in the game. Everything has a sound effect. Again, not great but not necessary in my POV.

Also very well done: instead of a (anti-addictive) slow build-up curve in the beginning of the game, the player starts with quite a high amount of cash so that the game starts as quickly as possible.

The enemy waves appear in a straight rhythm, so that they still can be balanced easily but do not confuse the player. Rhythm seems something all good games of the ’80s/early ’90s had but which gets lost more and more.

This is actually what it looks like when you start to become a good td player.


The “send next wave” button does not only help with the rhythm and flow of the player: a quicker / better player can adjust the game pace to his skill. It’s got the great feature that extra scores are awarded the earlier you send the next wave (making the game harder for you).

The preview bar of waves, showing the future of events is an often underestimated easy game play element. In Tower Defense, it is similar to the Tetris preview but not quite as helpful. It still is a tool for experienced players. They can adjust their flow and strategies to the upcoming enemies. Most simply by not “sending next waves” when it wouldn’t fit to the current situation, but also by building and upgrading towers fitting / in advance to upcoming enemy types. Additionally the preview bar of tower defense does not show more details (for example number of enemies, etc.). This makes it a little bit like a story line of adventure/RPG games – in which the player gets a forecast of the next battles/events/etc. by the storyline / dialogues between characters.

Desktop Tower Defense has great community functionality, of course a forum and the highscore list – which is superbly categorized. It has two (unique?) features. Group scores and view mazes. View mazes allows players to see the last status of the build towers when a player won/lost the game (when his score was entered into the highscore database, this is where the screenshots come from). This feature allows the community to look and discuss what strategies good players do and try to copy/mimic and improve the concepts.

The group scores are for me a feature that is most up-to-date for today’s massive global games (i.e. as in famous flash games). When entering your name into the highscore, you also need to enter a group name. You then appear in the global highscore table and also in the local table of your group. Classically highscores are so full with player entries, that (a) nobody finds himself, (b) nobody reaches the top 100 (1000, 10000, …) and (c) nobody can compare against somebody that is on his level, available for talk or interesting (as in “friendship” possible). The group scores feature is a ultra simple and very good working solution to all these problems. additionally the group scores feature reduces the impact of cheaters. cheaters that appear on the top places of the global highscore, can only appear in one local group. a cheater could cheat multiple times to spam all popular groups but very unlikely the group of you and your buddies.

Last but not least: i have really no critics on Desktop Tower Defense (i can even ignore to say anything about the ugly visuals :) .

Desktop Tower Defense

Daniel Renkel

Daniel 'sirleto' Renkel is a true indie game developer (at heart ;) and a part time simulation engineer (space- & aircrafts). He's studied computer science at the university of Darmstadt, Germany and has a background of 8 years as game developer (assistant projectmanager, game designer, associate producer and technical artist). He worked on a whole number of PC and console games including the Aquanox series. Visit for more information about this current android mobile phone games.

2 responses to “Desktop Tower Defense: Perfect Job”

  1. Daniel 'sirleto' Renkel

    old school rts skills at work in desktop tower defense:

    ps: crazy song

  2. Krystian Majewski

    Recently on Game Girl Advance


Game Design Reviews is a Blog used by a group of game designers from Germany to publish and discuss their thoughts on various games. The blog consists entirely of reviews of games. Each review focuses on the important game design ideas and concepts of that particular game. We also run a second, more informal Blog called Game Design Scrapbook.


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