While it's not uncommon for developers to readily share concept art, we don't always get specific details about how a game's design evolved throughout its development. In the case of Awesomenauts, Ronimo Games is already sharing both.
In a blog post, the original name of the project is revealed as OMG Space; doesn't have the same ring to it, but I dig the logo nonetheless. Early on, Ronimo's artists put together concept art that looked rather convincingly like in-game screenshots, such as the one shown above. Froggy G sure has come a long way.
While nice to look at, this original art direction wasn't the best for readability, particularly given how zoomed out the camera became for the final Awesomenauts. Other scrapped ideas include a multi-stage boss, melee and ranged attacks for every character, and roaming robots that served as towers. Neat!