Mars TD is an excellent tower defense game created by Taro, developer of the unfairly difficult platformer Super Ear Man Bros. The objective here is to build turrets around the map and protect your base from the incoming alien invasion, because every enemy that reaches the base will steal some gold from your resources. You will lose if you run out of gold at the end of a wave, although players are allowed to continue up to three times from the level they last attempted.

Three options are available to you whenever you click on a friendly unit on the map. Selecting the first choice upgrades the turret by one level, up to a maximum of five. The cost of upgrading a unit depends on how much experience points it requires before the level counter is automatically increased by one.

The second option is used to switch the location of two turrets. No cost is incurred if this action is taken in-between waves, but the amount of gold required to switch units during battles will be indicated inside the selection box. Turrets and walls can be sold by choosing the third button.

You're definitely missing out on something special if you let the lack of English text for menus and descriptions prevent you from playing one of the best tower defense games ever made. (screenshots)