Watch your energy indicator. You lose energy as you move, even if you run into a wall. It may look like you're not moving but unless you pressed the stop key, you're still consuming energy. Your robot can recharge itself if you stop and let it rest for a little while. Chips that are turned on cause your robot to use more energy. Make sure you turn off chips that you don't need.
Ice cubes are your friends! Though their main use is to cause viruses to reproduce slower, ice cubes can also be used as barricades, since viruses can't move through them. A well-placed ice cube can turn a corridor into a dead end, making it easier to corner the viruses that you want to kill. Don't get trapped by your own cubes, though - your robot can't move through them either and they take a while to melt.
