These multiplayer achievements drive us all crazy, right? Well I got a great message for you kids! You can do it all alone!

The only requirement you need to meet is:
Have THREE DIFFERENT gamepads! I used the XBOX360 ones. (in that case you also need a special PC receiver for these controllers)

First open the game. In the Main Menu, you won't probably see the Co-op mode. If you press Spacebar on your keyboard or A on one of your gamepads and the Co-op mode button will pop up. Click it. Connect all the controllers (press spacebar on keyboard or A on gamepads). Then press the buttons once again to 'get ready'. Once you're all ready, press spacebar or A button on one of your controllers to get in the game.



You should see some sort of Editor. Press A on each controller and spacebar on your Keyboard to 'join the game'. Now you can edit the game map which you'd like to play. To see the editing options, press the ZOOM button. I added one place for every player's color with ten tanks each, and a hangar for one of the places. This one I boosted up to 50 tanks. NECESSARY: I connected all the places so I can send my tanks in there (black thick lines). Once my map is done, I pressed SAVE and got back in the main menu via BACK button.

Once my map is done, I pressed SAVE and got back in the main menu. There I played the first singleplayer level. After I finished, I hit co-op mode again. I connected all 4 'players' (pressed A on each of 3 controller and spacebar on Keyboard), then got ready (same again) and made them join the game. Then I played for the one with most tanks and captured all the places until all the places share the same color.

Crowd achievemend should pop up. And if this was your last achievement to do, you should also get the Hundred percent achievement. Hooray!