Newborns usually sleep up to 20 hours a day. I know its weird since most people complain that a newborn is the hardest. I've found it actually one of the easiest stages. They wake up to eat frequently yes, but then they go right back to sleep.
If baby is having wet diapers, waking up to at least eat, and gaining weight there is no need to worry.
I guess each stage has it's pluses and minuses.