They used to be pretty worth it and balanced; for the most part, there was one achievement for opening the game worth £0.10, which they still do.
They changed it now so that all other achievements, if there are any, are only worth £0.10 or £0.15. It used to be that there was a £0.10 achievement that was easy to get, an £0.25 achievement, and a £0.50 achievement.
I blame all those people who took advantage of the system, cheated, and used SAM.
You all know who you are.
Rush Bros playfire rewards were awesome. I spent like one hour on the game, didn't know wtf I as doing, deleted it, didn't unlocked a single achievement.
I did all 22 achievements and received like 4 dollars worth of credit. Felt good.