I'm not going to lie, but I never watched the second one. I just didn't really get the humor of the first one.
There are a few things that I was confused, or just didn't like that much:
-Why are animals and Batman interacting with each other. I don't get it.
-You need to get a tripod, or keep the camera steady, cause when your stop-motion starts, the camera gets extremely shaky, and it's hard to focus on what's going on.
-You don't need to do stop-motion on everything. Having Batman jump off stuff, or a Batmobile that can actually roll on the ground, could just be filmed regularly.
-You have great sound effects, so why don't you just add voices to the character? I don't really like reading everything, when you seem to have the ability to add voices, but you just didn't. Work on character voices, and give a different voice for different characters. Maybe get some friends to help out.
-Make more convincing "set pieces". It's hard to imagine what's on screen, when your bar is a CD, drinks are chocolate, a skyscraper is a staircase, and you can clearly see your house in the movie. It feels like I'm actually playing with toys, when it should feel like I'm watching a movie with goofy toys in it. You see the difference?
It's not bad, I just don't get it, I guess. Not trying to be rude, but those were the things that stood out the most.