We were the only team at Riga, Latvia GGJ to use UE4. Here’s out game: http://globalgamejam.org/2017/games/submarine-waveblast
It’s a 4 player multiplayer submarine game, where you have to search for treasure avoid (or shoot with torpedo’s) other players and bring your treasure to your base for gold. (well, that was the idea, but some stuff might not be working, oops)