For anyone trying to 100% achievements in this game

[PFunk924]

The last achievement has nothing to do with the secret tapes. If you enter the code for the green lock, there is a bucket in there. Place the bucket under the dripping water and wait for it to fill all the way. Then pick up the flower pot that's next to it and interact with the bucket while holding the flower pot and a fish will come out of the bucket This will unlock the achievement "Splish Splash" for anyone that's missing the last hidden achievement.

[Pugo]

thanks!