It's gamemaker. If it's slow, that's unfortunately not my fault. All older game maker games have a tendency to run slow on some computers and fine on others. Sorry if it's running less than 60fps, there's nothing I can do :(
That's very surprising, I thought gamemaker was quite a fast engine in general. :) All good dude.
It is fast! It's just that games made with older versions of GameMaker have gotten slower over time (Skelemania was made in GameMaker 8). GameMaker: Studio and Studio 2 have improved a lot over past versions.