Efficient collision detection for a runner game

I’m making a 3D runner game for mobile devices (like temple run), and I want to know how should I check the collisions in an efficient way.
In my game, there will be around a maximum of 15-20 obstacles active at the same time to check collisions with, plus some items/powers ups. All of them have simple colliders, like boxes or capsules.
So, the question is, should I use…
A) physics system (this is, onColliderEnter function, and all similar things).
B) checking if colliders near to player overlaps with it every frame, with something such as: collider.bounds.Intersects(…)
C) Some cast from the player, like a capsuleCast, or some rayCasts every frame and checking the distance of collision point.
D) Any other option that I haven’t thought of.

Thank you very much!


Unity uses the PhysiX engine by envidia. I’d say it is pretty optimized.
Read the documentation on collider for information on how to set it up.