Cheesius I like it.
One suggestion I have is if you had a few more seperate buildings in the background so they're not all hopping up in complete unison, it would be better if they were all obviously seperate. A bit more work, but I think it would add a lot to it. Also, some sound, of course. Thirdly, you need to add a stop to the end, so it doesn't loop forever - unless you want a loop. When the giant one steps in, it's pretty obviously pixelly, might want to re-draw or re-scan that leg in higher resolution, but that's a pretty minor thing.
Beyond that, the only thing I can suggest is make it longer, but as you say, it's schoolwork. Keep up the good work.
