Here is the full list of all 9 Elasto Mania II achievements.
Complete Pack A
Complete Pack B
Complete Pack C
Complete Pack D
Collect all Bonus Helmets
Reach a total time of 1 hour with bonus helmets
Reach a total time of 1 hour 5 minutes with bonus helmets
Reach a total time of 1 hour 10 minutes with bonus helmets
Reach a total time of 1 hour 20 minutes with bonus helmets