Zackrifice

Made in 48 hours in course of Ludum Dare 43.

You are Zack! Someone starts talking to you to protect their altar. Then many zombies appear. You have to sacrifice some of your health points at the altar to get better weapons to fight against the incoming enemies, but luckily also receive some points after each wave. If the zombies destroy your altar, you won't get any more health points and won't be able to buy new weapons. If they destroy you... then you're dead.
Let's go Zack, Zackrifice yourself!!