Pitch Draft: Mechanised

Players use a toolset of parts to design battle machines. Design of the machines is entirely in the player's hands... there are no set slots where parts must go. Instead, players can place parts anywhere on a blueprint-style view. For rockets or guns or wheels to function though they must be connected to a power source, of which the player has a limited supply. Each power source is tied to a different trigger button on the keyboard or on the screen. When the player holds down a trigger button, the battle machine components that have been connected to that power source will be activated.
In this example when the player holds the 1 trigger, the two rocket engines will fire, shooting the machine towards the enemy and battering them with the shields the player has placed on the front of their machine.

I'm unsure if gravity is a good or bad idea for this game. If it was ignored, players could have much more freedom in their designs, and in the way their machines work. However, the inclusion of gravity reduces the play field to essentially one dimension of movement, two if the player invests specifically in vertical thrusters... which makes the AI design a simpler task, and also focuses more importance in the machine design, rather than the player's piloting skill.