I'm also having this issue. Is there anything past when you simulate your first simple creature?
So you've hooked up the pacemakers to the muscles like this, yes?
There's no content past that point yet. Part of the release I'm planning for tuesday will include some more manuals-a-la-lego-instruction-booklets, but the game is still mostly a sandbox.
I misunderstood some of the wording in the tutorial and accidentally hooked up one pacemaker to two different muscles. I feel the instructions could be clearer about this part. Other than that love the game so far, such a cool idea and I'm a big fan of the execution!