What is a game or games that you think are an absolute must-buy?

OG Kerbal Space Program is the best. The sequel, Kerbal Space Program 2, had a lot of missing features from the original KSP, and it is still in Early Access. The developer, Intercept Games, was also closed by Take-Two Interactive, and this game has not had any major update in months. It is clear that Take-Two has completely abandoned KSP 2, and it is still on sale. But it might not be for much longer, because it is literally on life support at this point, only getting patches and bug fixes.

Wouldn't be surprised if Kerbal Space Program 2 ends up getting delisted at some point in the future.