This is level 5 of the G-Tunnel.
There is a mixture of tiny one-tile platforms and slightly larger platforms. Obviously, you want to touch the large platforms as much as possible, but this is not always possible. To increase the chances of touching the large platforms, use the Bunny. You may know how this works already: in a safe area, do a few short hops and then one big long jump to get over tricky terrain.
If you don't have the Bunny, then use the Runner's short jumps to get over the smaller platforms, though you still want to touch the larger platforms as often as possible.
You can also use the Child and his long, far jumps to beat the level quite easily. If you narrowly miss the jump, the Child seems to make his way onto the platforms.
Finally, beware of the ice tiles giving you too much acceleration, making you overshoot.
This level was originally supposed to have boxes, but that idea was scrapped.