Endgame is something strange, lots of pistols, mountains of dead bodies. Another battle royale but it is more, than just a "don't copy it so obvious". I like barrel hijack mechanic, but can't it be a long-term gamemode. APB is MMO, but it is session based MMO with open world.
I thought, that riot will be something like the long conquest war for goods and guns, with random events. It needs a lot of buffs/nerfs/revorks, or a complete rethinking.
Anyway, good luck.