Attempting to make a smurf house cake for Min

Min wanted this particular smurf house cake for her birthday. I promised her I would try to make it, and this is the result.

Although I followed the recipe from The Aubergine Chef exactly (including the buttercream for the cake; the cake itself happened to use shortening) and used Satin Ice Fondant (i.e. store-bought fondant), the cake still turned out bumpy.  I'm guessing it's because I didn't put the cake in the freezer for 15 minutes before putting the fondant on the cake, so the buttercream wasn't solid enough?

Photos from my phone:

 

Reviews:

Cake

Texture: Soft, light, moist. (Grace, Me)

Taste: Taste isn't strong but matches buttercream nicely (Grace). I like the taste - not overpowering, just nice.

Buttercream

Texture: Fluffy, light, creamy.

Taste: Buttery and chocolatey.  Dad and zc found it too sweet. Grace jie loved it, especially the way it worked with the cake.

Overall

Grace Jie: Loved the way the sweet buttercream matched the not so sweet cake.
Zc: Nice but buttercream is a little too sweet such that a person won't want a second piece.