I really like the concept here of having to choose between waiting for gold to come in or liquidating a dragon to get money immediately. The biggest feedback I would say though is that the rate at which you gain money seems so high that the only reason to liquidate dragons was hitting the dragon limit rather than actually running out of gold. So slowing down the rate might force players to interact with the liquidate system more. As the other commenter mentioned too, some sound effects or music would help as well but overall a solid entry for the short time frame.