This room takes a lot of timing. Reducing GAMESPEED in the options menu can make it easier.
1. Wait until the first apple falls down. Quickly activate the first star switch when the apple is above the lower left switch block. The explosion will destroy the first four red blocks.
2. Activate the second switch when the second apple is above the upper left switch block.
3. Same thing for the third switch.
4. The last switch. If you use it at the right time the level is solved.