Edit: Below is the link of my uploaded video to prove this is an excellent way to get this achievement, any negative votes, you clearly are catastrophically doing the challenge completely wrong as I beat the achievement time over 37 seconds!
The best way and easiest way to get this achievement is to do the Stockpile level: Cooling Towers. This level is found in the Volk Area with the 3 big towers. (3 circles on the map: found around the centre of the map) Collecting all 100 orbs in under 2.30 is actually very possible to do with only 1 of the 2 players attempting this but both players must be at the starting position when the stockpile mini game starts for the achievement to count for both players. Reason being as I tried out the level a few times (about 3 times) on my own and started collecting the orbs from the first big tower first and then worked my way along from there and with only just a little bit of practice, I ended up completing it in approximately 2.15 as my best time, meaning 1 of the 2 players can just sit comfortably, however I strongly recommend both players attempt to get all the orbs in separate directions to make life more easier and for both players to get the achievements quicker without any struggle at all as all the orbs are in simple locations. Also to add note My agility rating was 4 star when attempting this, so I recommend both players have to have at least a 3 star agility rating if both are working together for this one to make this nice and straight forward. (Preferably, i'd recommend both players to have a 4 star agility rating for best results) Hope this helps! Good luck!