What's a word meaning "of or relating to video games" in the same way that cinematic is to film? I want to describe a bit of music as having video game like qualities, something more general than retro gaming blips and beeps, and find myself saying "video game-y." e.g., "the DOOM 2016 soundtrack has interesting influences. I hear allusions to previous entries in the series and many cues that feel unmistakably characteristic of video games. It sounds both cinematic and video game-y."
You are probably looking for ludic. Wikipedia gives the definition:
The adjective ludic originates from the Latin noun ludus, meaning "play, game, sport, pastime."
Oh, I love video games! Old video games sound the way they do because they use sound synthesizers. Doom in particular makes a very good example because the music was meant to be played on the Roland SC 55 Midi Synthesizer if I recall correctly, and there are various home console ports that would have used lower quality integrated synthesizers, like the S.N.E.S. which used the custom Nintendo S-SMP soundchip and and the Sega 32x which if I recall correctly would have utilized the Sega Genesis's Yamaha YM2612 F.M. synthesizer.
As such the obvious answer to this question is synthetic:
SYNTHET'ICAL, adjective Pertaining to synthesis; consisting in synthesis or composition; as the synthetic method of reasoning, as opposed to the analytical.
The American Dictionary of the English Language by Noah Webster
The only problem is that sound synthesizers aren't always used for video games, and when applied to music it's sometimes taken as a criticism. As such, you might want to use the phrase synthetic timbre. Timbre is a word meaning:
The quality of a sound independent of its pitch and volume.
Wikipedia even cites the words "synthetic timbre" on their Electronic Music page as being used in Sounding Art: Eight Literary Excursions through Electronic Music, Aldershot: Ashgate Publishing, Ltd, ISBN 0-7546-0426-8. Also before you read it, I should disclose that my pseudonym is a misnomer. I am not a musician by either trade or hobby.
[Sidebar: Right now I feel my citations are a little weak, which is because I'm busy. I'll fix them up later.]
word suffix that means "of or relating to" ?
(forming adjectives) in the style of; resembling.
"It sounds very video-game-esque."
I would say the word "cinematic" is a bit out of place, but still applies, as gaming often has "cinematic sequences." Although not relating to actual cinema or theater, the word can be applied loosely to video game soundtrack considering there are compositions for both film and game that are so similar. If you were writing about a soundtrack in a game, or even composing your own, you would likely want to use "cinematic game score" or something like that. It would be nice if there was a one word blanket for that term, but as far as I know it doesn't exist.