As Kevin stated, he's not completely happy with how the XP system works right now. Here's my suggestion to overhaul it to unlock characters.
How we unlock the new characters then?
Character would be unlocked by doing certain character-specific actions. It wouldn't be linear, any character could be unlocked at any given time. For example:
- Burn down an Optimus Pine with a torch, unlocks Willow.
- Dig up Wendy's ghost (special tomb marked by statue or "Here lies Wendy" carving), unlocks Wendy
- Destroy a 3 tier spider nest with your bare hands, unlocks Wolfgang
Burn down 50 trees, unlocks Willow. Un-burrow 3 ghosts, unlocks Wendy. Carry 64 stones simultaneously, unlocks Wolfgang.
But how do player find out about this?
Off course, for this to work we should be able to see the background image of each character before unlocking them, so you have a hint of what needs to be done. Willow is fairly easy to unlock by accident, who didn't burned a forest down? Once you unlock the first one, you can figure out the other ones.
Also, a hint system should be implemented. Each character would have 3 hint: A vague one, a more direct one and a rather obvious one. In order to encourage survival and discourage grinding, a new hint would be available for every 15 days survived. First the vague hints will appear, and once every character has a vague hint, the direct hints start unlocking. And so on.
90% off the players will run to the forums and read how to unlock them, but the 10% that figure it out themselves (either knowingly or by accident) will have their mind blown.
But what if..?
Ideas? Flaws? Let's hear them. Xacktastic already helped me refine my system, I can't wait to hear what you guys come up with.