Pure evil!

Finished it, got all stars, switches and treasures. 'To be continued...' but how?

The hardest of the Magma levels in my opinion. As the exit is far to the right (you could consider going left to get the star in the chest first)

The main tip here is to provide special consideration for exploding blocks, and consider dropping them off of the rocks into the magma instead of exploding them, unless they are right in the middle of the colored block section AND you won't set off a chain reaction of exploding rocks. Other than that, stay persistant, and plan your moves carefully.

One more point to mention is that the switch is on the extreme right of the screen so you have to go past te exit to reach it and come back.