If the blocks are different colors, than maybe if they have a certain color that would be associated to a certain special ability. For example, if you have a shade of blue for your player, you can go through water at a normal speed as opposed to being slower. Maybe even faster than the normal speed. If they're gray, maybe they can go through rocks. Then maybe these special things could have varying levels of likelihood of getting that power-up.
If the blocks are different colors, than maybe if they have a certain color that would be associated to a certain special ability. For example, if you have a shade of blue for your player, you can go through water at a normal speed as opposed to being slower. Maybe even faster than the normal speed. If they're gray, maybe they can go through rocks. Then maybe these special things could have varying levels of likelihood of getting that power-up.