Nice design and a good old game. Weekly challenges sound like a good addition, especially the bonuses for people who lost most.
Since it seems like a Bustabit script, I wanted to ask whether you obtained it from them with their permission.
I also think it's not fair to say that your house edge is 0.5% when it's actually 1% or 1.5% (I got confused on how much it is exactly) you take everything into consideration. Other than that - nice website, good luck!
It's a license website, you can see it here
https://www.bustabit.com/license.txtThe crash game house edge is 1% and reduced to 0.5% effective house edge via weekly challanges.
It is provably fair, the game runs on same crash point algorithm as current bustabit. ie. Bustabit v2 crash algorithm.