where can I find examples of the games you will be holding these contests?

leagueoflegends.com and here battle.net/hearthstone

Thank you for inviting me to your project. Your request of not using gradients , involve also not having color transition and depth. All the graphics of these tournament games, are more or less, volumetric, fantasy and action based on fine logo designs. This request will limit drastically the end result ,creativity and design... Would you reconsider this ? At least to be able to create a full color vesrion to use on the website and additional one color version maybe... Kind regards, Vlad

It's actually something I've been thinking about lately.
So yes I'm willing to let you use gradients.

Give it your best shot!