Only played up to the "I hated school..." cut scene.
Shooters aren't my thing but the story line holds so far. Has a nice classic graphics style. Maybe more dramatic and varied cut scenes to keep it interesting. Reload time is a serious pain but that's the challenge, right. Since the player is stationary at first maybe (if you haven't already) the player can have a chance to move vertically or horizontally by a couple spaces as they advance.
Keep it interesting. Weave incentives/plot twists into those cut scenes and levels: maybe have garbage cans or lockers and water fountains periodically be able to be shot open, spilling stuff that will block zombies in that direction for a few secs.
And if there's a zombie count, you gots'ta have medals.
Hope this helped. Looking forward to seeing more.