The links lead to #4 and #5, not #3 and #4.
I think you messed up the numbering system on Youtube.

#4 had pretty choppy animation, and there really wasn't much to it. There was also some focus-flicker, the set was very plain and basic, and *Gasp* it mixed Fleshies and Yellow. The joke could have been fleshed out and made into a creative little short, but the running time kept that from happening. I think the man's tone, and the pacing were the worst parts. And a snappy, but not necessarily fast, speech containing stuff like "All right guys, this is it, the big night, your big night, now get out there and do your best!" and stuff like that, but ending with the punchline, would have worked better and had a better build-up. Remember, jokes are (IMHO) quite reliant on the build-up. So much so that a good build-up can save a lame joke, or even make it better.

#5, Umm, is that some saying where you come from or what? 'Cuz I didn't really get it.
That would be quite awkward to say normally, and seemed engineered just for that joke.
The framing is is bit odd, and would be improved by bringing the camera down to face level. I've found that elevated camera angles don't look that great, and don't sell the "It's a real movie, just happening in Legoland" type aspect very well.

The character animation was fairly good, but they shook a bit much, and there seemed to be a tiny camera bump at the very beginning of that last shot.

This series is ok, but I'd like to see something a bit more substantial from you soon. Oftentimes flaws that show up in minute-long shorts, are more easily missed or overlooked in longer productions.

Series-wide, I think #1 and #2 had the best jokes, but were hindered a bit by shaky animation. These two also have those technical flaws, but lack the entertaining punchlines/stories. And I hope this doesn't offend you or anything, as I'm only trying to help. And don't mean any of this in a bad way.

Episode "5" suffered greatly in that there was no volume balance.  I could barely make out the voice, so I turned the volume up.  Then, BOOM!!!!  It shocked me... figuratively... and people in the next room were disturbed by it.  You've got to keep your levels in balance.  shame because I like the concept.