I often see a lot of confusion with regard to OpenBSD, either assimilate as a Linux distribution or mixed up with FreeBSD.
Let's be clear, OpenBSD is a stand alone operating system. It came as a fork of NetBSD in 1994, there isn't much things in common between the two nowadays.
While OpenBSD and the other BSDs are independant projects, they share some very old roots in their core, and regularly see source code changes in one being imported to another, but this is really a very small amount of the daily code changes though.
Let's do it quick, what can you find in OpenBSD?
It's used with success on workstations, either for personal or professional use. It's also widely used as a server, being for network services or just routing/filtering network!
All the innovations that happened in OpenBSD
If you never used OpenBSD, you can easily give it a try using the community made LiveCD/LiveUSB FuguIta!
Another way to easily try OpenBSD is to run it in a virtual machine.
Complete installation guide of OpenBSD
Please note that the VirtualBox additions are not available as their drivers never got written for OpenBSD.
You can install OpenBSD on your system, or a spare computers you don't use anymore. You need at least 48 MB of memory for it to work, and many architectures are supported like arm64, amd64, i386, sparc64, powerpc, riscv...
Complete installation guide of OpenBSD
You can rent an OpenBSD VM on OpenBSD Amsterdam, a company doing OpenBSD hosting on OpenBSD servers using the OpenBSD hypervisor! And they give money to the OpenBSD project for each VM they host!
I made a tutorial showing how to install GNOME, it's fairly easy!
How to install GNOME on OpenBSD (video tutorial)
This is actually possible, and always running native code to run video games.
OpenBSD Gaming video channel (peertube)
PlayOnBSD Games compatibility list
OpenBSD_gaming subreddit community