generally new gambling sites, no new sensations, almost all games are the same, slots, poker, dice, sports and so on, there are differences in bonuses and bets, to be sure, the bonus terms almost all gambling sites offer differently depending on the level of your deposit and the game you play there.
Agreed most new casinos are just the same with the older existing casinos if we look at the provided games.
Promotion and other offers that make new sites may differ from the other casinos but it is rare to see newly launched casino to have more attractive offers than the older one.
If you are looking for luck on a new gambling site, you are totally wrong, every type of game you must master and have a strategy to achieve success, if you expect a new gambling site for your luck, that's wrong understanding, I've tried, no luck on the new site, if you don't understand and master the game.
I have no idea what do you mean by mastering the game here, because most casinos games are pure luck based game.
No matter how great you know/understand about the game as well as your strategy, the result will be based on your luck.
Mastering the game wont change your luck unless you are referring to games where skills are involved such as Poker or Sports Betting.