It's more likely than you think.
Not much to say. River_City is a publicly useable RP room. It's set in a city, but it's entirely freeform. Thematically, people there are used to things like Godzilla wandering about doing battle with giant robots, random street fights breaking out and beaten up punks turning into coins, space fighters soaring over head and doing battle with weird and crazy enemy forces and so on.
You can do preeetty much anything you like. Municipal forces repair citywide damage at a rate of knots thanks to how efficient they are, emergency forces almost seem like they're run by ninjas, the police are able to take plenty of time off because of other groups who deal with criminals, superpowered criminals, alien incursions, and giant monster attacks. (remember those giant mecha? Yeah. them.)
You can be a random civillian just trying to make his or her way through life, a heroic individual intent on saving people's lives, such as a magical girl, a mecha pilot, a hot blooded vigilante, or some costumed nutcase...
Or you can be a villanous individual; kidnap girlfriends, send out legions of mooks to take over the city, and send a ransom note to people you haven't seen since high school taunting them that you have their girlfriend and you're holding the city to ransom! Or in your evil hide out send out dangerous killer robots to take over various facilities! Or lurk in your huge evil castle and send out legions of monsters. Or just fly around the city causing havok. Your imagination is pretty much your limit

The only rules are as follows:
First and foremost, follow the goddamn site rules. Do not forget those.Rule of Cool and Rule of Funny apply heavily, Leave your seriousness at the door.
Don't be a munchkin or godmoder. It's not a competition.
HAVE FUN. But make sure others can have fun too! Don't run roughshod over everyone else!
Be Excellent to Each Other.
If you're going to attempt to blow up the entire city remember the Municipal Peacekeeping Force of River City will send out their best and brightest, to Macross Missile Mayhem you. It will be like fuckin' bangai-o, I swear. They can't afford to rebuild the ENTIRE city at once. So play relatively nice.

Inspirations are various Video Games, Paul Robertson, Megatokyo Pre the exile of Rodney Caston, Megas XLR, Excel Saga, Cromartie High School... you get the idea.
Humans welcome, anthros, elves, dwarves, smooth voiced <s>robots</s>tough guys, Freddie Mercury lookalikes, hyperkinetic ADHD servants to shadowy underground organisations lead by the fabulous handsome wonderful leader Ilpalazzo, cute little critters, timetravelling mecha pilots, and anything else welcome too.
And yes you can if you REAAAALLLY want to, play a tentacle monster, or a knight from another world, and that is entirely up to you. If it's funny or cool and it doesn't run roughshod over anybody else's good time, it's perfectly fine. If you can set up things that makes sure everyone has a good time, that's fuckin' awesome, and you deserve a hug/hifive/beer/brofist (delete as applicable).
I won't always be around to run it, but feel free to have fun in mine or any other (potential) mods' absence.
Go nuts.
Have fun.
