Spacewar

Last game for the 20 Games Challenge and first try at a multiplayer game: it wasn't easy but we gave it a shot nonetheless.

                                                  

It needs a little bit of tinkering with the settings to work:

After clicking on Play and selecting the driver, you will need to enter your IP under 'Server IP' and your router's port, which must be opened beforehand. Your friend will have to do the same, but in the box below.

Once you have entered the data, click on 'Host New Game.

Player 2 will need to click on 'Join as Client.

                                                

Alternatively, it's much simpler: if you have Steam open, you can use it. Click on 'Use Steam' -> 'Host P2P Game,' while Player 2 should click on 'List Lobbies' and then click on the lobby that appears.