Maybe I'm a noob but I can't beat the final boss... :(
Lol yeah he was tough spent most of the stream dying. Eventually got him by running to the beginning of the level when he starts calling the zombie 9 year old to help him. Clear them out from that side first then go to the next.
BONUS ME.. I mean TIP lol: Dont jump after his laser attack because he'll be too high for you the break the glass the npcs are trapped in.