PlayerProgression

Purpose
Progression rewards players and can motivate them to keep retrying.

General details

 * Intersession progression (in between playsessions):
 * All players in a session get an amount of experience (from here on called xp) based on at what wave they are game over
 * Based on the number of xp players gain they either level up or they don't
 * If they do level up the player will be able to unlock traps and upgrades for those traps. Afterwards they see this:
 * If they do not level up they just see how much xp they gained and statistics
 * So in between game sessions, you unlock things you can use to progress further with within actual sessions.
 * (Possible future goal:) Reaching high waves could give the player special rewards like:
 * Cosmetic changes like skins/emotes/golden guns


 * Session progression (within one session)
 * You can upgrade traps and turrets within a session to an upgraded version. Each trap can be upgraded one of two options.
 * Achievements (planned)
 * Rewards to do very specific things
 * Rewards to do impressive things
 * Motivates achievement hunters

UI/UX

 * Game over screen
 * Level up/unlocked screen
 * Score and statistics in the game over screen
 * Sounds

Programming details

 * Every user uses local progression in multiplayer sessions.
 * XP amount for wave reached should be easily tweakable