Demo Balance Patch — Underground Security Inc Steam update #521001

Small balance patch for the demoBoss difficulty scaled down - we were finding new players were struggling with the difficulty spike a bit too much Emerald ore cost: 3 -> 2 - unfortunately, this means if you update the client while having an active save, there may be a bit of weirdness where existing ores will have the old cost, while newly spawned ores will have the new costRain of arrows: base damage decreased 60 -> 45 Summon Demon Prince: base health / damage increased from 125% -> 150% Dungeon Walls no longer have a construction cost and can be placed for freeAdded a more robust save system to prevent corrupted saves