Pick up the 2 by 4 and knock the heads off of those red zombies. There are some zombies chained to the wall. When they flash they spit slime in your path so simply wait and jump over the slime.
There is some bats...kill them then some spikes pop up just wait and then walk past them when they pop down. Shortly after that two large head zombies appear kill them and then kill their flying heads then climb the ladder and go to the first boss.
BOSS: This is not so hard just stand in the middle of the room and kick any slugs that come near you.
