Transformers!
For aeons Cybertron has been at war. Decepticon and Autobots fighting for control. Each winning and losing in a cycle. Decepticon tyrants overthrown and Autobot leaders brought low. This battle has claimed countless lives til it seemed destined to take the very life of the planet itself.
This led to the great search for Energon led by Optimus Prime. Aboard the Ark they left Cybertron but they did not do so alone. An elite force of Decepticons followed them led by Megatron. When a suitable source of Energon was found they attacked the Ark. This led to both ships being crippled. Autobot and Decepticon escaped in their stasis pods - raining down across the solar system but most of them landed on a very familiar blue planet.
That was several million years ago. Now something has awakened the survivors from their long sleep and the Cybertronian War begins again.
This game is heavily influenced by G1 and Beast Wars. It utilizes a homemade (though not by me) system that is linked to in game. It's easy, free, and covers the Transformers quite well. No experience required.
What is required is a burning desire for some giant robot violence and cartoonish nostalgia. If you like Transformers come give the game a look.