Consider this, Desktop pc has SSD drive and no program running on top of OS (or running program whose data I don't need to save). If I just switch off the power button rather than properly shut downing the pc (Say it is just for fun), what problem it may arise?
Any data not yet written to disk will be lost.
No program or service will properly shut down leaving all sorts of temporary files, pid files and the lot all over your system. Which may interfere with proper startup of some services on the next boot.
I also suspect you'll be prompted to perform a file system check next time you boot.
Off course if it's just for fun and you don't care about the health of the system I'd say try it and report back here what you learn.