ScreamRide

To complete Series 1 you must play every level of; Scream rider, demolition, and engineer
You'll get enough commendations to unlock the next series but don't move on to the next series until you have passed all four of the levels for the three options.

Don't be deterred by the Bonus Challenges, as they are just bonus and are not required for this achievement. You essentially just have to complete each level once by riding the coaster until the end in SCREAMRIDER levels, or for just completing each demolition in the DEMOLITION EXPERT levels. Then, for ENGINEER levels, you must complete the minimum criteria that is listed just below the description of the level name (marked in yellow). It says CRITERIA and then a few requirements that must be met in order for the level to be complete (e.g. for the first ENGINEER level the criteria is "Complete the Coaster", so you just have to build the coaster until it attaches just behind the beginning of the coaster so that the coaster is a full loop (during engineering, the auto-complete button (D-pad up) can help with this). Hint: if you're feeling lazy, for Engineer level 1, you can simply auto-complete from the start and test the ride (D-pad down) to complete the level.)). It gets a little more complicated moving forward into each Engineer level. For the last one, I just popped this by slowly building downward in a snake-like fashion back-and-forth making S shapes so that I could slowly waste the minimum (1,200M) length of track needed while still using gravity for speed so that I exhausted 1,200 track as I made my way to the beginning of the track and still made it back to the beginning of track (using auto-complete).
This achieve is easier than you may expect as the bonuses are not needed.
Good luck!