Hacking to the Gate (TV Size)
Steins;Gate
Chiyomaru Shikura (composer, writer), Isoe Toshimichi (arranger), Kanako Itou (vocals)

Since the anime aired on Japanese television, the flashing in the OP animation must have passed some sort of epilepsy inspection and should be safe for most to watch.

But just in case, I've enabled the FLASHING LIGHTS WARNING.

Difficulties:
Normal - 4
Hard - 6
Extreme - 8

Charter
JoldNoteC

Cover source:
https://www.imdb.com/title/tt1910272/mediaviewer/rm670595840/

Background source:
https://vignette.wikia.nocookie.net/steins-gate/images/5/50/Wiki-background/revision/latest?cb=20191014215021

Video source:
https://www.youtube.com/watch?v=TR3ma_60-m4
シュタインズ・ゲート OP 「Hacking to the Gate」
志村道夫
Alternate videos:
Fan-remake by Katsuhira
https://www.youtube.com/watch?v=gUT4a9beW3Q
Steins;Gate Opening but it's remade in 4K
Katsuhira