I want to run this game but I dunno how I would record it, what's the cheapest way to record this game?

If your have a phone or something you can use that to record your run.

For example @DiamondcrafterA record/stream his runs with a tablet.

For me, the phone or the tablet is the cheapest method for recording runs. Cap card are more expensive.

A camera lol

As was stated above, streaming through a phone/tablet is the cheapest option. If you're looking for a cheap and decent quality capture card, the GV-USB2 is a good choice also.