Act 1 introduces the primary mechanics of Marble Zone. You'll immediately encounter Baton Badniks (fire-breathing robots) and Burrobot Badniks (drilling robots). Navigate through crumbling blocks and use the pushable blocks to activate switches or create new paths. Many sections involve riding moving platforms over lava. Time your jumps carefully to avoid falling into the molten rock.
There's a section where you need to push a block onto a switch to open a gate. Further on, you'll find a series of platforms that sink into lava. Move quickly across them. Look for hidden passages behind waterfalls or crumbling walls; these often contain extra rings or a shield. The key to this Act is patience and observation. Don't rush into unknown areas, as the lava is unforgiving. Keep an eye out for air bubbles in underwater sections, as they are less frequent here.