There had been two paths: The left path immediately reached a room with a firefly, but it was surrounded by a lot of mud blocks. The right path is much longer, but easier to access due to 2 moves being added each time after advancing one room.
Now there is only a single path, which is the one to the right.
Also the number of moves has been changed, from 28 to only nine, which is absolutely ridiculous, so now the level can only be made with some extra moves.
Exit the boards as quickly as you can, being carful that you don't waste too many moves on level 4. Try and save your colour bomb until the last room as the firefly is surrounded by broken stone. You shouldn't need to use extra moves for this level, but sometimes the layout of the gems will be critical, and that's just down to luck.