I believe Hamachi was mainly a level 2 VPN, perfect for transporting IPX, which was really mainstream for LAN games of the 90s.

This seems to handle layer 2/3 since they mention support for TUN/Tap interfaces, but I guess 99% of people will just create IP tunnels, layer 2 is not the hot thing anymore.

Also, Hamachi was not decentralized from what I remember.

What is presented here reminds me a lot of n2n.