When I want to test an IT infrastructure technology -- for education, for proof-of-concept, or for problem recreation -- I conduct my tests in a laboratory environment. In many cases, that lab can be a virtual machine, or for network technologies, a suite of interconnected virtual machines.
While its not a "game", I can "play" with quite complicated environments, and not interfere with any production platform. My usual platform for these tests is
emulators/qemu on an OpenBSD workstation. You could do the same. The cost (other than time) is $0 if your virtual environment does not require commercial products.
The most complicated virtual lab I've created under qemu was a proof-of-concept for a high availability web application infrastructure. There were web servers, application servers, database servers, and servers for network load balancing. The server farms were at multiple geographic locations, and used IPSec VPNs for site-to-site communication. This entire complex ran on a single i386 workstation with 2 cores and 2 GB of RAM.
Not everything can be tested in a virtual environment. Some things must be tested on physical platforms. As you are a student, it is possible your school may have labs you may be able to use, either aligned with a specific class you are taking, or for use in ongoing research. For the latter, perhaps you can apply for a post with one of your professors as a research assistant.