My first comment ever on this site! While I am no one to judge since I haven't uploaded anything yet, I would say that you should check out a guy on youtube called Draw with Jazza. I dropped out of art school a long time ago and recently decided that I would like to be an independent animator and his channel is so awesome for people who are just starting out or getting back into animation! Start with some basics and build upon them. Why I chose my first comment to be on yours, I really don't know :) It's probably because it was so short and I had to sit through that Professor Layton ad which seems so long lol. But best of luck to you! The best advice that I can probably give is to save any sort of tests that you might think people want to see for your own learning vernacular. Develop any ideas you might have even further to where you feel motivated to push yourself to the limit! And don't be afraid to map it out ahead of time, like in a script. I see a lot of people on this site, just throw stuff together, which can be a funny spur of the moment thing, but I've personally learned that the more time you spend on something the more you learn and the better you become!

Cake! Aliens love cake! Cakes have layers.

It doesnt offer much, While it is nice to see for a first try, If you do remake it in possibly a few years when you get better. Add some sound and/or voice. Its too short so it isnt anything really interesting. So if you can, Try to make it abit more slower and longer. So the tank can shoot the missile at the UFO. Hope it helped abit.. Sorry. Have to be strict but i am honest.

Well, the harshness is unfortunately going to come with the first animation. The animation was well put together, it just lacked substance and the "I need to watch this" factor. It was technically an animation, but there was no point in me watching it, it wasn't funny, serious, experimental, beautiful, marketing, or anything like that. It just kind of exists and that's what brings it down.