For PC, for now there's no update past 1.35. But, here's the links:
SFS 1.35 32 bit
SFS 1.35 64 bit
This is the original files, not pirated nor compromised in any way. I am a former admin on this forum so download this freely.
Gecko Gekkota, current admin will attest to this.
Edit: To unlock the expansion, press "T" in build mode.