This is a walkthrough for Star Hill in Super Mario RPG Remake. It includes sub-events and wishes for Star Hill in Mario RPG.
Star Hill Recommended Party
Recommended Party
Mario
Whimsical Hammer
Work Pants
Anti-Transform Badge
Peach
Slap Glove
Polka Dress
Wake Up Pin
Bowser
Chomp
Happy Shell
Zoom Shoes
Peach joins your party at Star Hill. She is an excellent healer, so swap her in for Mallow. You can buy armor for Bowser in Marrymore, so be sure to get it. Many enemies are weak to fire, so use Mario's Fireball to defeat them.
Star Hill Walkthrough Chart
Hear about Star Hill from Frog Sage

At Tadpole Pond, you can hear about the location of the next Star Piece from Frog Sage. After the conversation, the next map after Marrymore will be added.
Go get the Cricket Cracker
If talking to Frog Sage doesn't let you proceed, you might not have completed the event to give him the Cricket Cracker. First, go to the item shop in Mushroom Kingdom, get the Cricket Cracker, and come back.
Star Hill has no treasure chests or bosses

There's an explanation by Geno at the entrance. In Star Hill, monsters appear, but there are no boss battles and no treasure chests, so you can explore at your leisure.
Light the Star Flowers to open the door

When you examine a Star Flower, it lights up. Light all the Star Flowers in the map, and a door will appear on a star with a keyhole. Once you enter the door, you cannot return to the previous map.
Normal attacks are forbidden on star-shaped Rupees

Be careful when fighting the Rupees that appear. Star-shaped Rupees will counter normal attacks with an instant-death attack. Their weakness is fire, so defeat them with Mario's Fireball.
You can hear wishes from stars with faces

The stars with faces scattered throughout the map contain the wishes of characters appearing in Mario RPG. Try to guess whose wish it is.
Wishes of defeated bosses also appear

Wishes from bosses you've defeated so far will start to appear.
Find the Star Piece in Map 3

The Star Piece is in the northeast of the map you visit after opening the star door with a keyhole three times. There are no particular events after obtaining it, so you can exit to the world map.
Sub-Events and Trivia
Mallow's Wish

If you examine a wish in Map 2, you can hear the wish 'I want to stop being a crybaby.' Mallow appears and tries to distract you from seeing the wish.
Mallow's Mother's Wish

If you examine a wish in Map 3, you can hear the wish 'I want Mallow to come back.' You'll see Mallow reaffirm his decision to reunite with his parents due to their wish.
Luigi?'s Wish

If you examine a wish in Map 3, you can hear the wish 'I want to be useful to my older brother.' This is thought to be the wish of Mario's younger brother, Luigi, and connects to him giving hints for progression from the shadows of the castle.