Favorite robot designing games

Colobot
http://www.ceebot.com/colobot/index-e.php
It's a real-time 3D strategy game where you collect resources, make buildings and create units but with an extra twist. All of your units (except for your human which is the only unit capable of making buildings) can run program scripts (using a programming language based off Java). This is great for anyone that wants to learn or just practice computer programming. Create programs for your units to find and bring back resources, attack the enemy automatically or just routine mainenance tasks. There is an online forum with a number of user-made levels and programs (some of the programs there were my creations) and a discussion area (which has been fairly dead lately as the game came out years ago). There is talk of one user making an unofficial sequel, but it's unknown if that work is continuing or if it's been abandoned.

Mindrover
http://www.mindrover.com/
The premise is that you are a bored scientist on a remote off-world lab using company bots for entertainment. You are given the choice of 3 different chassis (wheeled, tracked or hovercraft) and three different sizes from which to build your robot. There are many different scenarios. Most of which are combat based or a race of some kind. You add components such as engines, weapons and sensors to the exterior and then program your bot using drag-and-drop logic components that you drag "wires" between to pass information. It's also possible to write programs in a language called "ICE", but you cannot do this in-game. The interface and gameplay enviroment is in 3D, but plays on a strictly 2D plane.

Robot Arena 2
http://www.robotarena.com/
This is a computer-game version of the popular Robot Battle TV shows where teams design a "robot" and then compete against other robots in tournaments. The game is played in a fully 3D enviroment with a decent physics engine. You can load a premade robot if you want, but the fun is in creating your own design. To start, you make a 2D outline of your chassis baseplate. Then you determine the height and tweak the shape of the upper chassis plate so you can have a wedge-shaped bot or whatever. Then you attach parts to the robot. Batteries and a control board are a requirement plus you'll need one or more motors with a wheel(or you might be more creative) attached for movement. You can also add weapons, pneumatic pistons (plus an air tank to fuel it) amoung other things. Anthing that sticks out of the chassis can be damaged and broken off in battle. Next, you set up the wiring. There is no programming so everything is wired to a remote control that you design as well. switches on the remote can be assigned to keyboard keys or a joystick. Lastly, you can put a custom paintjob on your creation. You can either use the limited in-game tool or export a chassis template and then use your favorite paint program to do something more fancy and import it back into the game. Features online multiplayer with up to 4 players in a match. My favorite creation is a rather slow, heavy and bulky creation called Fender Bender that uses dual spinning icepick disks that lifts and tosses around all but the heaviest of opponents. Even bots that will operate upside-down can easily be thrown out of the ring or pinned against the wall.