I'll help you out. ^-^

Goal 1: Mission for the Mann

- Play Moogoo Monkey
Find Det. Dan and he will say that he needs an "inside man." You have to go to Salty's Riverboat to play the Moogoo Monkey minigame. Once you play a game, Guiseppi will come talk to you and tell you to check the bulletin board.

- Follow the directions on the bulletin board
Go to the Miniopolis Chronicle and look at the bulletin board. The first post will say to search the shrubbery near the museum. When you do, you will find a slip of paper that reads "the answer you seek lies beyond the grave." That means you have to go to the graveyard. (NOTE: you must complete goal 3 before you can do any more) Go to the second little section of the graveyard that was
blocked off earlier. Search the tombstones until you find another note. It pretty much says you have to go talk to Berkley Clodd. (hence the "feather in his hat") He will give you a briefcase.

- Give the mysterious briefcase to Det. Dan
Find Dan and give it to him, and he will rig it with a microphone.

- Give the rigged briefcase to Giuseppi
Now take the briefcase to Guiseppi and give it to him. He makes a comment about a million simoleans... Bet you wish you still had that case, huh? But at least now you will be able to play Moogoo Monkey.

[Credit to this guide]

Hope I helped!

~Jordan