There's a major and a minor bug that are currently present in Early Access.
Major: Laptops running without a dedicated graphics card are likely to run the game in slow motion. The small group of testers we've contacted, have reported that the game would run in slow motion on laptops if they had them run off their integrated graphics cards. The issue would be fixed once they switched to the laptops dedicated graphics cards (mostly gaming and workstation laptops). No such issue has been spotted with desktops, so it has something to do with the laptops turning down the performance of graphics chips. There have been a number of similar reports with other developers working with this engine on Laptops when they were unplugged from the power adapter. In some cases the issue was fixed when the laptop were plugged back into the outlets. We're investigating the cause of the issue but by the looks of it, it may be an engine issue so we will contact the Engine developers to figure out a solution.
Minor:
When you add player 1, then player 2, and then delete player 1, the game will not recognize some generic menu button presses for menu navigation. This is due to the game looking for player 1 as the HOST player - one with the control over the menus and interface. When player 1 is deleted, it's slot remains empty until it's filled, at which point that player becomes the host. We'll be fixing this in the next update, when there are more than 1 player, deleting player 1 will shift all the players down 1 slot, ensuring that Player 1 (HOST) position will never remain empty. For the time being, should you remove player 1 - all you have to do is get one of the other players to remove and re-add themselves with the controller. The game will automatically place them into the first available slot.