In our universe there are some number of physical constants that cannot be determined from maths alone, but only measured. If you go about changing these physical constants then we don't have physics as we know it (change 1/137 to 1/140 and electromagnetics no longer works). You get some totally different physics of which there may be nothing more complicated than hydrogen, or maybe hydrogen doesn't even exist at all.
https://en.wikipedia.org/wiki/Fine-structure_constant