Besides the official events, the Wii U version of Mario & Sonic at the Rio 2016 Olympic Games is also going to add a twist on the typical party games the series is known for. This new mode is called Heroes Showdown, and it's a competitive offering which has Nintendo and Sega characters facing off against each other.
The developers are inviting players to challenge a friend on this mode, in search of an affinity to each team/universe. You first choose your side - with Mario and Sonic as captains, naturally - and then the CPU organises the duel by randomly choosing the rest of the roster and the events to compete across.
After each trial the wining team gets a bonus card that can then be used to boost their performance in the next challenge, such as "remove a member from the blue team" or "power up two team mates", etc. This is important because the winner is not the team that wins the most events, but the one with more heroes standing at the end.
Mario & Sonic at the Rio 2016 Olympic Games launches for Wii U on June 24, and is already available for 3DS. This is the Heroes Showdown trailer: