I have a little bit on my personal wallet, Of course, I have to exchange it first, that makes shrink than before.
I don't find they mentioned specifically against gambling. but for sure before being linked to kinguin, KYC is one we have to do.
Kinguin is also a place to sell skin and games, I don't know if possible to withdraw them from 500play to Kinguin?.
You can check out the prohibited list here. Pretty much
persona non grata since we casinos generally fall under their red zone:
PayPal prohibits the following activities, even where the specific activity is lawful and/or is not legally defined as gambling, unless the transactions are associated with an approved merchant.
Games of chance and games of skill –Includes any activity with an entry fee and a prize, regardless of whether the outcome is determined by chance or skill.
Casino games -Include (but are not limited to) the following virtual or physical games: baccarat, blackjack, craps, faro, keno, pachinko, pai gow, poker (whether or not it is considered a game of skill in the gambler's jurisdiction), roulette, sic bo, slot machines, or wheel of fortune.
Sports books or sports betting –Includes placing bets on actual sporting events against a bookmaker or through a betting exchange.
Horse or greyhound racing –Includes gambling on the following types of races:
Yada yada yada...
Source:
https://www.paypal.com/us/smarthelp/article/What-gambling-activities-does-PayPal-prohibit-FAQ915The games/ software are to be activated based on the platform they're hosted on (e.g. Origin)
. Yeah, I always try to play most in the weekends when that promo is live, a lot easier to level up! 
