This little trailer is made using only open source software in less than a day. I'm the first to say it's not that good, but I think it serves the purpose, that is, to introduce the game and give the idea to viewers how the game plays. The software I used are Gimp, Inkscape, Audacity, and kdenlive. They are running on Fedora.
I think I will write a bit when I have time how use these tools together to make a video clip like this. Don't expect much, this is the first time I edited any video clip in more than 10 years (the last time I did I was in college, using Adobe Premiere). By the way, this is how the whole thing was set up. Just tripod, Sony Nex 3, some afternoon soft light, and a water bucket to keep the tripos still :)