Adding energy-saving products to your house can benefit the economy, the environment and your living comfort. However, these products are very costly, and many people cannot afford them using their own savings. There exist several options for funding these projects, but people do not take advantage of such due to lack of information and the common negative view on using external funding. Psychological objections on taking loans include future time perspective, perception of short time rewards and connotation of loans itself. This paper presents a serious game aimed at changing people's mindset on taking loans to retrofit energy into their homes; Supreme Green Time Machine is a tycoon game in which you can acquire energy-saving products for your home. A main mechanic in the game is the opportunity to take loans to fund the purchase of these upgrades. Combined with other underlying mechanics, such as the time progress and social feedback, the game targets the different psychological objections to long term loans for home retrofitting. From a preliminary evaluation, we conclude that Supreme Green Time Machine effectively succeeds in making players more positive towards using loans to retrofit their homes.