Ah, tower defense genre. How you taunt with your towers, your upgrades, your evolving strategies. How you draw the player in with simple creatures to dispatch with ease, then pull the carpet away to reveal how that carefully pre-planned strategy was full of holes. How you put shame to preparations and defensive design with the greatest of ease. And look — a giant walking octopus which is out of water and also on Mars.
Coated in retro pixelated graphics and pipingly sharp music, Mars TD by Taro begins in a casually simplistic manner: Select one of the two available towers, place it on the map, and complete level one. Get more coins, buy another tower, and clobber the aliens in level two. Repeat. From the simple beginnings stem two obvious strategies — buy lots of towers or upgrade the few which you already have.
The first strategy is strength by numbers. The second is simply strength by strength, but also comes with an interesting quirk. For each alien destroyed, you receive coins. Not only do you get to keep those coins, but that same amount is deducted from the kill-tower's upgrade score. A particularly deadly tower will soon be very cheap to upgrade. It's up to you whether to upgrade quickly, which is more expensive, or to leave a tower weaker for longer, which gives the increasingly strong aliens a chance to break through your defenses.
To purchase a tower, select it from the right-hand column, and place it on the map. Allow the alien bodies to pile up. When a tower is selected on-map, the top-most option in the menu is the Upgrade button, with the current upgrade cost. The lowest option is the Sale value. These either increase or decrease depending on the current strength and efficiency of the tower, so keep an eye on the numbers.
The middle option is Move. This lets you swap one tower with another, if you should so desire. This option is free between rounds, but the cost varies if you want to do it in-game. Moving to a new, unoccupied spot will require that you purchase a wall — this is the square option in the tower select menu — then swap it with a tower. When your towers have been set adequately, click the Current Wave button to start the round. If a level is running badly, select the button marked "menu" then the middle option to restart the level. Just note that this will cost you one of your Continues.
Analysis: The variety of towers, whose weapons increase in ferocity and ability with upgrades — for example a freeze shot comes from the second tower when strong enough — really brings an extra element of strategy into Mars TD. Depending on what you purchase and upgrade, and when, your resulting arsenal can be vastly different from turn to turn. Planning from the beginning and being able to modify your plans on-the-fly as you adapt to the current level's intensity brings added depth to the later levels. While the language barrier may be a tad daunting, there is nothing so frightening that a little clicksperimentation can't handle it. Besides, your enemies are walking octopi and disembodied rotating dog heads that bounce, to name just two varieties. What's not to like about that? Those with a penchant for strategy and a flair for retro will really enjoy this game. There is a lot to uncover.