They all appear to look good and congrats for making your own.
1. The text (on the right hand side) seems to move to fast and to me should be a little bigger maybe something more readable(bigger font perhaps- unless that's the look you were going for.)
2. A few of the images on the bottom banner appear to be varying. One is a transparent .png while the others are having a black BG. (My guess is the ones with a black background were copied straight from a google webpage and pasted into aftereffects.) To stop the black background from appearing, look for items followed by "png." [EX.) minecraft chest png] Then once you open the image(full view) right click and save it to your computer. Then add those files within AE. Re-size them and have fun animating them.
3. Try to make the second one seamless. GIF's are always better when they transition smoothly and for eternity.