I'm personally not a fan of the wisps. Why do I need a powerup to do a spindash?
I liked the old TV Monitors with fire bubbles and bombs. Didn't really inhibit the gameplay. It's Sonic, I want to blast through, I want to go, well, fast. I don't like how the wisps slowed down gameplay. Let's go, go, go, aww I have to use this hovercraft thing to scale this wall? Like, that's cool in Mario, but that's not what I want in Sonic. I have to use this blue cube to change the active platforms? What is this, Mighty Switch Force?
I liked Laser, LIghtning, and Frenzy. I have qualms with everything else though.
I would like Spike, but if I remember correctly, you can't spindash normally in Sonic Colours, it really does bother me that they made it a powerup. Like spindashing on walls and ceilings you can't normally get on without momentum? Spindashing and breaking through hard metal? Those were awesome. But I need it to spindash at all, like, come on.
Basically rogerregorroger's thoughts, so, if you watch his Sonic Dissected series at all, I very much agree with him and will probably end up restating his thoughts.