I didn't play the first one so I can't compare. But overall good game mechanics. I played through to about level 12 then I started getting bored. If there were a story or some way to get me more invested in the character(s) I'd think this would be more fun.
I really like how you engaged the NPCs to defend themselves with the weapons crates. I just wish they'd help each other out when getting attacked. Even melee attacking the zombie that's attacking the NPC.
As to Sharpnova's comment about the music: I'm no fan of this kind of music but I just ignored it. It was only playing at the beginning of the game, not during gameplay. They must have a chip on their shoulder or something. Do what makes you happy and to hell with the rest.
Good job sir/madam