You really went all out with the pilot episode and I really enjoyed the entire thing, really! The opening theme song made me crack up and I could tell what a nice well done series this would be right from that. The voice acting was nicely done, even the aliens or villains or whatever we shall call them. The plot was really funny with John starting out on the couch with his arm wanting to go fight crime while he just wants to sit on a chair. The sound effects sounded a bit like a Hanna-Barbara cartoon at times which was still really good. I laughed out so hard when John's Arm was talking to those little yellowish aliens and then the arm goes back to being just something used for pressing the remote by John. Excellent quality of animation as well.
It was confusing and quite hard to follow at times with the voices usually being so high pitch and talking at a much to fast speed to fully understand, I would only get the gist of what was said after the next scene started. Also after the movie I went to grab a drink when it just continued to play in a loop, also the movie started without me having to press any play button which was annoying which I had to restart. It doesn't really give any hooking feeling to make the viewer want to instantly see another episode unfortunately.
Still a very well done episode, it's a great pilot that is totally hilarious with very fine quality within sound and animation, the pace of timing was perfect I'd just recommend making slower paced more clear voices as well as something louring viewers into watching more episodes. Very well done though, hope to see more John's Arm episodes in the future!