Counter-Strike: aim accuracy and incredible keyboard-mouse hands eye coordination. Also, being able to grind and mental simulations of possibilities to be ready against them. It is like chess but with consequences.

Need For Speed: Most Wanted, Carbon, Underground and Underground 2 require you to use manual gears if you want to improve. Also, those titles involve a lot of manual car equipment tuning. The precision required on keyboard is almost equivalent to the combined precision you would need for Counter-Strike with both keyboard and mouse.

Pocket Tanks: incredible amount of guesstimation with projectile classical physics, and being creative with the use of weaponry. To make it harder, I always play against CPU-10 with always selecting “Random” weapons to learn to make the most of what I have.

Mario Forever community fanmakes: Yes, that Mario Forever game from 2005 has a giant community. The community exists across USA, Canada, Europe, Russia, China, Vietnam, South America and elsewhere. Some of the fanmakes have levels and battles against Bowser that can last 20-30 minutes with no mistakes allowed. BLOODY FUCKING HARD. Go through the community forum via this, to dive down this deep rabbit hole: https://download.marioforever.net/mf-games-en.html If you think Mario is easy, check this out https://youtube.com/watch?v=Oqv2JBGi4EA or https://youtube.com/watch?v=lpphf_gsYaQ or https://youtube.com/watch?v=P6ZIBZtOT30