The Riders of the Rustlands Add-on for Trials Fusion has 5 achievements worth 250 gamerscore.
Beat level -1 in 'The Magnetic 10' challenge on 'Junkyard Funk'
Complete the 'Wormfood' challenge on 'Gone to Waste'
Complete the 'Slumdog Billionaire' challenge on 'Rags to Riches'
Find all 3 squirrels on Riders of the Rustlands
Pass all tracks on Riders of the Rustlands