First thing, your site has pretty huge of house edge, although it is has PvP games, it is not suppose to have this house edge, 10% for PvP games is hard. And btw through my understanding about the bonus, there is 15 stars which is if you lose and winning it will increase right? And to earn bronze tier you will need 100 HTP, let assume you win 50 and lose 50 then, still it does not benefit us here. Losing $50 to get $10? And we never know yet about the next tier the difficulty will be increased for sure
This website is fully fair (Has MD5 hash) and if you play with strategy you can make 100 HTP just by 5$ , you are not have to lose your money