The Game Genie code 'Fun house is free' should work for getting to the FUN HOUSE level.
Log entries
2021-04-04
[11758]
This game is very charming and the graphics is adorable, much like the previous game.
[11757]
Malu and I worked together on beating the 4 short but difficult minigames, which gives you 4 golden coins that gives you access to the FUN HOUSE. This level has infinite continues, so we decided to stop and cheat our way to it another day.
2021-04-11
[11781]
completed the game (MiSTer).
We did it! After almost 2 hours of practice, we beat the FUN HOUSE level! As usual for NES games, the last level was a nail-bitingly stressful affair, with 3 hit points and no checkpoints.