>>11910175The actual flaw in this picture is not understanding the substance here. Sure, there's more track in the Sonic level, but the game naturally tends to funnel the player downwards thanks to gravity. Plus with how fast Sonic's speed is, the only way you're getting to the top realistically is by making almost-random jumps in high speed areas until you've played the game over and over again to memorize WHERE you should be making those button presses and why. Plus, even ignoring all of that, Sonic will just tear through the level in mere seconds as you just simply run and press down to spin around, which will nullify 100% of the enemies on the level.
On the other hand, the Mario level appears more simple, but you're interacting more with each obstacle. Mario doesn't have Sonic's invulnerability during high speed runs, and only can do damage with a direct attack downwards unlike Sonic being able to hit from all angels. This makes it so that Mario is going to have to spend more time going a bit slower and interacting with each object/enemy on a more personal level.
tl;dr While the Mario level is seemingly flatter, it's simplistic appearance is deceptive, and the complexity is in that you'll be interacting with ALL the obstacles on a more closer basis as a casual.