Here's an ambitious idea for all of ya. Just for shits and giggles, mostly.
It has zero chance of making it in, but what the heck, right?
Names: Robotnik vs SonicDescription: While testing his Super Sonic Smashing Spring-powered Snowglobe one day, Robotnik accidentally creates a wormhole to another galaxy that's filled with robotic fellows.
Being the robot obsessed man that he is, he is greatly fascinated by this world, and decides to pay it a little visit.
Not too long afterwards, the mad scientist quickly befriends all the robots by giving them all tune ups, shiny coats of paint, and by giving them all a prrrrromotions.
Soon enough, even becomes so popular that the quirky little dictator is asked to judge the upcoming robot tournament!
Meanwhile, Sonic, who has just been kicked out of Brawl for making people's ears bleed with his godawful taunts, needs someone to take his anger out on, so he wanders over to Robotnik's place to beat him up, as always.
In doing so, he stumbles upon the portal, enters this new world, decides that all the robots belong to Robotnik, and then attacks, killing everything in sight!
Not wanting to lose all of his new robot friends, Robotnik gathers a team of survivors, and then heads out to kill the hedgehog he hates so much once and for all...
tl:dr - Sonic invades and tries to kill every robot master he comes across! So they ask a fat bastard with great knowledge on robotics to help them save the day.
Robotnik
Skin: Hardman, Woodman, Diveman or Windman. Whatever works.
Health: Average.
Weapon: PINGAS laser - Basically like the laser buster weapon in M8BDM, only without the charging. The cooldown period and damage dealt is around the same length as the laser buster, if not buffed up a little.
Rage: Mean Bean Machine - He jumps into his Egg-O-matic and can now fly around for about 10 seconds, constantly dropping chocolate covered hard boiled egg bombs everywhere at his own leisure.
Super Jump: 'Tis just a regular super jump, but with an earthquake effect once he lands, damaging everyone near him with his fat, egg shaped bottom.
Other stuff: If he dies, then all the survivors lose! Which is why they need to work together to protect Robotnik and take down the ultimate evil... Sonic.
Sound clips: Robotnik from the Adventures of Sonic the Hedgehog cartoon. And maybe Sonic Adventure, for extra lulz.
Sonic The Hedgehog
Skin: Blue Quickman
Health: Below average.
Weapon: Spin attack - Sonic rolls along the ground, causing damage to whoever he hits. It only takes away about a third of a survivor's health though, to make up for his annoying speed.
If he kills someone using this method, they turn into a Flicky, who will then aid him.
Rage: Super Sonic racing - He goes Super Sonic and dashes forwards, killing all in his path (or doing massive damage to Robotnik). This attack also causes everyone who is killed to turn into flickys.
Super Jump: He uses a spring to jump upwards. The spring lingers for a few seconds afterwards, meaning that others can use it too.
Other stuff: He's as fast as shit, running around at almost Quick Man like speeds.
Sound clips: Sonic from Super Smash Brothers Brawl, certainly.
Flicky
Skin: Either Beat or Tenguman. Or perhaps just a simple Megaman.
Health: Very low.
Weapon: Peck - Works in the same way as a claw, although it only does half the damage.
Rage: None
Super Jump: They hop upwards, like a normal super jump.
Other stuff: Whenever a survivor is destroyed by one of Sonic's attacks, they turn into a Flicky. Quite like Ra Thor and his minions.
Sound clips: Birds? I dunno.
Music for the hale:Sonic CD boss:
or Sonic 2 Boss:
or maybe even this sexy beast:
Like I said, this has pretty much zero chance of making it in, and may actually be impossible to program, but hey! I hope it provides some inspiration, at the very least. If not a laugh or two.
Totally loving that Sentinel idea though. As well as Pharaoh Man and Invincible Air man. If anything should make it in, those should.