Up on the Rooftops is the sixteenth and final level of the Frost difficulty in Holiday Lemmings 1994.
Strategy[]
Turn the first Lemming into an Athlete and let it drop down to ground level. Have it build against the snowball before the Exit portal to turn him left then build once to create a safety net for the other Lemmings. Let it walk off his ramp and build against the snow to turn him back towards the exit. Have one Lemming going right build to get over the steel block holding the others in and raise the release rate to 99.