I liked the few shorts I've been able to catch from time to time. Yes they're a bit too fast but they don't have a lot of time also. Hopefully when the series actually starts(Either has 15 minute shows or the full run time) maybe they can slow things down. And hopefully actually get the story/world building done.
Also to my knowledge this first showed up on the CN app that did shows/games/etc. So yeah it's aimed at little kids/teens.
Edit: Also they're brother and sister? Huh, didn't know that.