Continuing on from earlier today.

This is the 4th world, the Twin Bridges. You only need to complete one of the bridges to beat the game (both if you want get everything.) It's a pretty small area if you only want to do the normal route.

This is the 4th boss, Ludwig Von Koopa (Named after Ludvig Von Beethoven who was a 1780's icon...OK, I'll go and correct what I wrote in part 1.) He shoots fireballs so watch out for those. The three bonks on the head rule is still in effect here.

The Forrest of Illusion is your next spot. This stage can get confusing as some paths literally lead you nowhere. The wiggler's make their first Mario appearance in this land as well.

Roy Koopa is the next boss to face (named after rock singer Roy Orbison. He's even got his glasses as well.) Very similar to the second battle but tougher as expected.

Chocolate Island sounds delicious and it's also the next stage! It also has Chocolate Island 2, one of the toughest secrets to find in the game. After making you way through their, you'll face the next boss

Wendy O. Koopa (a play of the name Wendy O. Williams, the famous 80's punk rocker) has a boss setup very similar to Lemmy's stage although there are more fireballs to avoid.
The third and final part to be up in the next 1-2 hours.