Overall nice game to play. This game could make it into a proper game just fine.
But the problem is the control and maybe difficulty.
I had a hard time trying to move up and down while trying to remember the key for placing different types of wall.
Potentially, it's possible to win the game easily with just placing the walls and slowly killing the zombies.
I think we can just cut off the human shooting side out and focus on building the walls and maybe placing turrets like TD games...yeah, Plant VS Zombies kind of thing.