This instruction requires you to install two 3rd party programs. Download these programs only from trusted sources provided in my guide. By downloading them from other sources you put yourself at risk of downloading a virus or trojan program.

1) Download and install current version of vJoy from Sourceforge[sourceforge.net].
2) Download current version of x360ce from GitGub[github.com].
3) Put x360ce.exe in your RBS folder (use your Windows search function if you don't know how to find it).

1) Launch vJoyConf.exe ("Configure vJoy" in Start menu).
2) Make sure "Action" set to "Configure", "Target Device" at "1", press "Apply".
3) After new device was created, change "Target Device" to "2", press "Apply".
4) After new device was created, change "Target Device" to "3", press "Apply".
5) Delete xinput1_3.dll
6) Open x360ce.exe, previously copied into RBS folder.
7) Application will ask you to create new xinput1_3.dll, press "Yes".
8) Application will ask you to create x360ce.ini, press "Yes".
9) Application will search internet database for gamepad configuration presets, press "Next" and "Finish" for each one. After that you should be able to see green lights next to "Controller 1", "Controller 2" and "Controller 3" tabs at the top of the application.
9a) If this is not the case, and you you grey lights instead of green, try repeating steps "2-4"
10) Close vJoyConf.exe and x360ce.exe

1) Launch vJoyFeeder.exe ("vJoy Feeder" in Start menu).
2) Launch Really Big Sky.
3) Select Device 1 in vJoy Feeder screen and press first button in "Buttons" grid. You should get message "Player 2 joined" on Really Big Sky screen. If you can't access vJoy Feeder app because of the Really Big Sky window, go to Options and change window mode from fullscreen windowed.
4) Select Device 2 in vJoy Feeder screen and press first button in "Buttons" grid. You should get message "Player 3 joined" on Really Big Sky screen.
5) Select Device 3 in vJoy Feeder screen and press first button in "Buttons" grid. You should get message "Player 4 joined" on Really Big Sky screen.
6) Start the game as usual and choose "Boss Rush" gamemode. You will get the achievement if you can kill the boss without letting any of your ships die. It may take you a few tries, since you can't actually control the ships, so I recommend taking "+50 to shield" perk to give you more time.