The animation and voice acting needs work.
But you'll get there eventually with practice.
Not bad for your first cartoon. The "walking on sunshine" sequence was well animated. I think technically the animation was average.
I have a few problems though. The voice acting is a big one; dull voice acting can really suck the soul out of jokes. You need to sound more enthusiastic, or in character...you don't have to be extremely loud to do this either. Nothing is funny, either (to me). You have some memes, and two references to ponies, which felt like you were pandering. The tnt house bit was predictable, and I think it would've been funnier if we saw David in rainbow heaven than have you explain it to us.
I don't if the plot was supposed to be apart of a story or just gags coming after each other but I think it would've been better with a clear story.
Eh. It was an alright flash. However, I feel as if this video was more of an inside joke than anything. MineCraft seemed to only be the sprinkles instead of the whole product. There's nothing wrong with that, but when it's advertised as a MineCraft flash and there's barely anything to do with MineCraft in the video, it can be kind of jarring. I know that there were bits that resembled MineCraft, and I do give you props for not going with the typical Skeleton or Creeper joke after getting some diamonds, but it just felt uninspired.
Also, the voice acting was somewhat off. It sounded like some of the characters were just talking into the mic while being monotone. From a viewer's perspective, this can throw off the immersion of the animation and makes the situation seem less credible. If loudness is an issue, then I'd recommend doing your voice acting while very few people are in your house/college dorm. It'll allow you to be a little more realistic in your delivery instead of just speaking softly.
Generally, I see a lot of potential in this. The animation quality is decent (it's certainly better than what mine would be. :P), and the plot on paper seemed really good. However, like DragonPrince1337 said, work on the voice acting and humor in the future. I honestly didn't laugh all that much throughout the movie because everything seemed almost a little too expected while some jokes came completely out of left field. It's incredibly jarring and can leave some people completely confused. However, under the faults I presented, I can still clearly see a good movie and for a first animation, that's a great start. Keep working at it and try your best to make your next submissions better. I'm sure you'll get lots better in the future if you keep working at it! ^.^
I like it. for the future work on your humor and voice acting
VERY FUNNY BUT THE VOICES WERENT THAT GREAT KINDA BLAND AND BORING BUT GOOD ARTWORK AND MY FAVIORTE ARTIST IS UNKNOWN LIKE SERIOUSLY I LIKE ALL ARTISTS BUT NOT PICONJO HE TRASH