'I like what you're doing here a lot
Only real suggestion is add the credits like you said, and also try using a normal person instead of a stick. People at newgrounds tend to not like sticks for some reason, but it would be pretty easy to draw a semi-okay person. THe animation in the later half is pretty good, but 90% of portal voters won't wait that long to vote, so maybe some more eye candy earlier on. I really like it though.