The One Letter at a Time word game! >:3

[UltraMario]

Buns

 

[Paper Yoshi]

Bus

 

[UltraMario]

Mus

 

[MCS]

That's not a word but an abbreviation for museum/music so I'll count it.

Mush

 

[Paper Yoshi]

Much

 

[UltraMario]

Such

 

[Paper Yoshi]

Suck

 

[UltraMario]

Muck

 

[MCS]

F*ck

 

[Paper Yoshi]

Luck

 

[UltraMario]

Tuck

 

[Paper Yoshi]

Truck