Overdroid

We originally didnt spot which game Overdroid was a remake of through playing it, but were informed its the robot transfer part of Paradroid. It has traits of Tron and the slightly newer Rez (which is hardly retro now is it!) but that doesnt stop it being a good game all the same.
You have to hack your way into various CPUs (each CPU = a level) by changing the colour of the blocks surrounding it from red to blue. Sometimes you cannot change a block directly because its linked to an adjacent block, so you have to turn that instead.
What you have is a 3D spherical tile puzzle where one action changes another element. All the while this is going on defences are flying around the CPU and your energy is being drained with each pulse. With this said, enjoy...