Easy “better Together” Achievement:
All that’s required to gain this achievement is to beat the last level again, the asteroid level, with a co-op player. You can simulate a gamepad if you don’t have one, using a combination of vjoy to create a virtual gamepad and x360ce to make it an xbox controller. If you map the virtual gamepad to the same keys you control rex with in the game, the two players will more or less stay together in the level, making it a lot easier to control. However the level doesn’t fail if one player dies, so you can also use different controls for both players and just have any other person help you out, or swap between the two, using the 5 second invulnerability on any player that dies to get them to a safe place before swapping to the other. You also don’t have to get the good ending. Just get to the bomb room and then wait out the timer and get the ‘bad’ ending, that will be enough.