Feature prestige

New system is added: Feature Prestige.

Get 1 prestige point for every 1M cleared sectors. Prestige features (limited amount, mostly high level) to increase max level, price per level is increased too.

P.S. I'm still alive but have some health issues lately (not serious). Working on new game, got a bit stuck and tired, so decided to add prestige system i was talking about some time ago to TD. For those who interested i'll definitely post in discord about test version for new game when it's ready, no ETA now :)

Have fun!