Your argument doesn't make the point you think it does. Having the spindash doesn't mean the environment and terrain is made irrelevant. "Changing the philosophy of the game" is even more subjective an argument than "the spindash is a mistake", and that's before you consider whether changing the philosophy of the game is even a negative or positive development. That sounds like "I don't like it being available" to me. Hence why I keep simplifying your counterpoints and the majority of the arguments against the spindash in this thread to "I don't like it". I'm not arguing in "bad faith". If you played Sonic 1 without spindashing even if you could, it's the same damn game than if you played it without the spindash being available. The only mechanical difference is that it takes longer for you to look down. So why is it a mistake for it to be available? There's nothing (of note or worth) you could do with the spindash that you can't do without, and this is true up to Sonic 3 where you only need it to operate simple gimmicks. So what's the problem , exactly? What would Sonic 3 look like without a spindash, and how is that better?