Sonic's 18th Birthday ^_^

[Rökkan]

Actually, Sonic 1 (and 2 and 3 in doses) had loads of arbitary obstacles where you had to stop what you were doing and break/defeat something to continue.

Marble Zone, Carnival Night Zone, and Sandpolis Zone immediately come to mind, but there are probably more if I took the time to think about it.

You have to give me an example of Sonic 1. Sonic 1 was planned with this on mind.

Still, those small gimmicks didn't break the pace like having to stop, switch formation, press a button to destroy an object, then switch back, then run.

Green hill zone had breakable walls if I recall correctly, and lets not forget they originally planned to have the wrecking ball Eggman used as a movable object, but scrapped

Spring yard zone actually had you push a button to make a certain platform in certain areas (Which kind of makes on of your opinions false)

heh @ bold part
You don't have to stop to get through the breakable walls, if you had played Sonic 1 you'd know it. Run + down, then you jump and regain acceleration after you land.
And what the wrecking ball has to do with anything here, it's such an early development concept.

and again, I quote:

Still, those small gimmicks didn't break the pace like having to stop, switch formation, press a button to destroy an object, then switch back, then run.