I hope the powers that be don't mind me updating the title of this thread, because I thought I'd add my thoughts of the Transformers RPG here rather than create a new thread.
I'm guessing that many of us here will be more familiar with Transformers than G.I.JOE. The one thing I really like about the Essence20 is how flexible it can be. The same rules are applied to G.I.JOE and Transformers without changing the base system. You could easily do a G.I.JOE/Transformers/Power Rangers crossover game with very little effort, as everything is handled the same over all three games. The Transformers RPG is set just after the arrival of the Transformers on Earth, at the end of the Great War on Cybertron. This means you can use any of the number of continuities from the various media.
The Transformers RPG follows the same principle as the G.I.JOE when it comes to character creation. It has a class and level structure, but with the added emphasis on each Role. A role has two focuses options: For example, a Gunner can focus on Gunslinger or Sniper. Plus you can pick an Influence such as Former Senator or Gladiator, which act as your bots background and an Origin which determines your chassis type such as Cutter (aquatic vehicle) or Seeker (aircraft). Your chassis is your alt-mode and whether it be a snazzy sports car or military truck or helicopter, this is the bread and butter of your Transformer.
Some really cool concepts from the Transformers RPG and Essence 20 I like:
1. You can gain a Perk to allow you to have a human companion. This in essence gives you a secondary character, albeit a person who isn't really a match for a Transformer in a fight. However, having a human companion can be very useful in certain circumstances such as going to places where your Transformer cannot go. Pick this one carefully, as you could end up with a Hang Up if you lose your human companion.
2. The Modemaster role allows you to have Mini-Cons or grants you the ability to gain a second alt-mode like a Triple Changer. A great example of a Modemaster is the Decepticon Soundwave and his cassettes such as Ravage or Laserbeak. Mini-Cons also act like secondary characters.
3. You have Health instead of Hit Points and you have a much lower amount. However, you start off with more base Health than a Joe does in G.I.JOE. Your health can be increased by ranking up your Conditioning skill. The games uses the term "Defeated" instead of dying or dead and what's more, you can be revived after you have been defeated in a number of ways. However, most weapons and attacks will inflict 1 point of damage and there are various damage types.
4. The number of actions you can take in a turn is based on your Speed Essence score and you can take a standard action, a move action, or a free actions as an action. The number of free actions you can take is equal to your Speed -2. If you have Speed 1 you're going to have to pick between a standard action or a move action. This makes you rather slow. However, you can sacrifice your standard action for two free actions or an additional move action.