People are freaking out on Youtube about 3 main things:
1) The goofy robot. At the end of the day it's Star Wars, Jar-jar binks, R2D2 and other comedic characters have always been in it, it's a family film after all. I actually think the design is kinda cool haha
2) The lightsaber. Every good baddy has a signature weapon. Darth Maul had a double sided one, Dooku had a curved hilt. I think people are freaking out over nothing.
3) The black storm trooper. People don't seem to know that after episode 3 the empire hired regular people as stormtroopers, not clones. The actor is John Boyega, one of the most promising young acting talents from the UK.
I personally still hold high hopes.