Thanks for playing and rating the game!
Please allow me to elaborate on some of your comments.
The original idea was a more traditional deck builder, with permanent cards just like you mentioned. However, due to time constraints we decided that this wasn't quite possible to design and implement. Our inexperience with audio software and design also shows in the lack of music tracks.
I agree that some of the HUD isn't as clear as it should be. Examples are the lack of a faith counter (merely being a +x next to the pink icon, whereas a progress bar or number would have been nice) and the unclear counter for the Gift (the x/2000 next to the house icon).
Your last comment somewhat confuses me; did you perhaps not use science to buy new cards by clicking the blue orb (again, unclear UI) or did you just have such a high card turnover that your deck got bloated with bad cards?
Either way, thanks for all the feedback. It has shown us that we have a lot of room for improvement yet.
I'll make sure to play and rate your game!