Zombies are really fast, random weapon box doesn;t work. Doors won't open, can't walk up inclines nor stairs. Heal;th doesn't regen.
7/10 because it's really tough so that makes it fun.
Playing in the browser I couldn't see any customization effects take place. I don't see a suggestion box but the buttons are odd. Playing on windows 10 desktop in google chrome browser restarting the level didn't always work when pressing "R" on the keyboard (qwerty usb) and if I fell off the world/died pressing x or clicking the button in the upper right would always take you back to the main menu. If I didn't click the button before I died to restart, I would be sent to the menu again. I would say that maybe changing that would be helpful.
Side note, you entered this to a "Remake" game jam. This was posted 340 days ago when the jam started about 30 hours ago.