It is. It’s actually the first entry in the Science Adventure series. Steins;Gate comes after, though it also works as a standalone story. Robotics;Notes has a lot more references to Chaos;Head.

Chaos;Head is a visual novel I’m tempted to recommend specifically for this type of situation. The plot revolves around a protagonist with the power to make his delusions into reality. Lots of mind-fuckery. It’d probably be a trip to experience while sick.

Augmented Steam has a ton of useful features, including better filters