Players will be able to unlock extra weapons from multiplayer skirmishes, taking these into the single player adventure or using them against human opponents instead.
Here's the multiplayer fact sheet from Nintendo Europe:
Aside from a sprawling Solo odyssey, Kid Icarus: Uprising for Nintendo 3DS delivers exciting multiplayer modes allowing you to play Together with friends locally or online.
You can choose Nearby for Local Play over a local wireless connection or choose the option Far Away to play online over the Internet. You can search for friends online and join their matches or play against players all around the world.
Playing Together allows you to acquire new weapons. These can be used in the Solo adventure or to upgrade your current weapon for the next multiplayer battle! The large variety of weapons allows for all sorts of different gameplay styles so bring your best game and show off your skills!
Light vs. Dark
In Light vs. Dark mode a 3-on-3* team battle is fought. Whenever a Fighter is defeated, his Team Life Gauge decreases according to the value of the weapon this player was using. The Fighter that’s defeated when the Team Life Gauge gets entirely depleted will turn into a powerful Angel. The team that manages to defeat the other team’s Angel wins the battle!
In Free-for-All mode everyone fights against everyone else! Up to 6 players* pick their favourite weapon and powers and attempt to defeat as many opponents as they can within the time limit. Defeating players with a higher-value weapon increases the score even more.
*If there are less than 6 players in the game, CPU players will round out the remaining slots.