How do you beat Fusionfall

There are a lot of ways to do this. The last missions are in level 36, which is when you fight Fuse. The most well known way to level up is to do guide missions or world missions. Doing races in infected zones can get you some fusion matter, too. Don't be afraid of switching guides because you still keep the guide mission rewards, but you can't use them. I switch around with guides because some levels take longer to finish than others. If you need help, team up with some friends to do missions and other stuff. Try to get the best armor and weapons in your level.
Hope this helps. BTW, on Fusionfall, I'm Alpha Aerovein.