While not officially supported anymore yet still playable, Awesomenauts is and has been virtually the only 2D Moba in any form of relevance. Despite it not only fulfilling an interesting niche for platformer fans that want to combine the ability usage and team play of Mobas, it also is very aesthetically pleasing with its strong character designs that not only look great, but also are very easy to pick up and play within the game. Fans of Mobas, even now, should give Awesomenauts a shot as it provides its own unique thrill and twist on the genre.
I really loved this game before they changed how leveling and perks worked. You used to be able to pick any mid fight, but then they changed that. With that and the leveling changes, comebacks became a thing of the past and it just became a snowballing shitshow. I'll always fondly remember the game from before that period, which I'd rate like 4.5/5, but the state it is in after is just shit.