Is this a Boss based game ?

So i have been following the game since its first trailer and through all the gameplays/trailers i have noticed a worrying pattern which is pretty obvious but no one have talked about ... 99% of what the Devs are showing are just boss fights.. where is the actual game ?? i feel that the game is just too good to be true and will end up with a very short game made of tens of boss fights tied together of a couple of arenas ... any thoughts on that ?