Act 2 continues with the same themes but with increased complexity. You'll encounter more elaborate moving platform sequences and sections where the lava level rises and falls. Pay close attention to the timing of these environmental hazards. There are also more Spikes (stationary spike traps) to avoid; use your Spin Dash to clear them if possible, or jump over them carefully.
A significant portion of this Act involves riding a raft through a lava river. You'll need to jump off and on to collect rings and avoid obstacles. There's a hidden 1-Up Monitor in this Act: after a long descent down a vertical shaft with moving blocks, look for a small opening to the left at the bottom. It requires a precise jump to reach. This Act demands careful platforming and quick reflexes, especially during the rising lava sections. Always try to keep a good stock of rings.