On Twitter a few hours ago, I got this sob story from a greenhorn dev: People keep stealing my ideas without my permission and they don't even credit me!
Well, you're not the brightest bulb... Here's a tip for all devs beginner to veteran: Do not ever share your ideas, not even with your identical twin brother. You have no friends in this industry. And you should act like you have no friends in this industry. The game development scene is a dog-eat-dog world. Your best friend will stab you in the back, here. The more vague you can be about your game, the better.
"It's like Castlevania."
"It uses some mechanics from the original Zelda."
"It's a platformer that has a retro feel."
"It's a game where you push buttons and stuff happens."
If you're openly talking about your ideas before they've even been started, expect nothing less than a faster, more talented dev swiping it. (Or less talented.) I understand wanting to share your ideas, but take it from an idea hoarder: you're better off not saying anything. Not even big AAA devs openly spout their ideas. Do you honestly think Chrono Trigger wouldn't have ended up on the Genesis if Nintendo had been talking about it before they ever started the project?
Look at what happened with Phil Fish. The mechanics for Fez were stolen from someone else. Someone who trusted him. Hell, I didn't even utter a word about my book until it was finished.
Rule of thumb: If it's not 30% done, shut up!