It’s not a safety issue. At least not a physical one. Depending on the game it could cause emotional problems. Rage, depression, addiction are all possible. You should consult a qualified mental health professional if you are, or become, concerned.

Oh. You meant safe for the computer…

The types of games you like to play shouldn’t be an issue even with truly ancient hardware (over 20 years old) so long as it was written for your OS/hardware combination. Compatibility layers (VMs, emulators and the like) can enable you to run software that is not compatible with your hardware or primary OS. As far as the hardware goes, depending on the game it may just not run, but worst case, the game may have bad frame rates rendering it effectively unplayable. Possibly leading to the above mental health issues.

In short, you’re unlikely to damage the computer.