You will find that Mount Must Dash is a bit of a quick level, as you will be utilizing dash panels throughout the entire thing. At the beginning of the level, you can climb to the top of the nearby tree to get a power-up. If you’re big, this will be a Super Bell and the Cat Suit will come in handy for the end of the level, so you might need it. Begin heading right, using the dash panels and jump panels, while avoiding the Biddybuds you will run into along the way. When you reach the fork in the road, stick to the bottom portion and don’t touch jump when you drop to some lower donut blocks, as you will collect Green Star #1 along them.
Not long after the Green Star, you will run into the end of this section, so take the Warp Box to the next part. Slide down the ramp (sliding defeats the enemies), touch the Checkpoint Flag, then begin sprinting up the next hill. At the top, the game will want you to jump over the gap, but drop down into it and enter the Mystery Box to find a bonus area. Here, you have 10 seconds to catch a rabbit and grab Green Star #2, so make use of the dash panels to quickly do this. After emerging from the bonus room, continue to the right.
As soon as you see a jump panel, use it to reach some trampolines in the air that will launch you up and into the Stamp. Right after the Stamp will be the final hill, where there will be a jump panel at the end of it. Use this and the Cat Suit to reach the ledge behind the Warp Box, which has Green Star #3 on it. If you don’t reach it in this manner, you should be able to reach it by simply climbing the wall with the Cat Suit. Use the Warp Box for the final area, where you will be using the dash panels and jump panel at the end to reach the Goal Pole.