In Ancient Isles, the playable characters are stuck running down the level's road and can only move left and right between the road's four lanes (akin to the Quick Step). While running, the player can pick up powerups from Item Boxes and utilize the gimmicks native to this track.
Ancient Isles has many environmental obstacles which the player can either jump over, roll under or move around. Running into one of these obstacles will result in the player taking damage and lose some of their Rings. Falling into bottomless pits on the other hand forces the player to restart from an earlier point on the track.
The racers begin by running down a large hill that rises up again, and has a series of Conveyor Belts placed at the end of it. They will then enter a long stretch of track containing a large number of obstacles and some Dash Panels set in the racers' paths. The next section contains alternating ground and Grind Rail sections that lead into a longer Grind Rail section containing spikes and Aero-Chasers, which in turn leads to a section of forward-facing Conveyor Belts. The two lanes on either side alternate between having Conveyor Belts and normal ground with Rings and Item Boxes, providing the racers with an opportunity to quickly run through the section.
The next stretch of a track is a long obstacle course with a brief Grind Rail section placed in the middle, leading to a large corkscrew that soon goes into a shuttle loop. Beyond this loop lies the final area of the track, which is a mostly empty section containing few obstacles and Item Boxes. The finish line can be found directly ahead.