Yea, I really have no experience with any computer stuff, but this Terrarium game seems interesting, but I am not sure if I am even correct on this, but it seems as if you need to save your codes as a dll, but I do not know how to save it as a dll... could someone please help me out?

Just open the proprties of your project, and set the output type to Class Library.

Just open the proprties of your project, and set the output type to Class Library.

How do I set the output type?

In the Solution Explorer window, right-click on your project and select Properties. There's a dropdown labeled output type, select class library there.

If you're having this kind of problem, though, you might want to start with some simpler applications than Terrarium.

Yeah... But anyways, thanks for your help.