Hi there Tamatalk!
Recently, I found an amazing listing on eBay selling all 12 of the additional "sold separately" figures that attach to the top of the Tama-Go to unlock games, food and occasionally, items.
I haven't seen a lot of discussion about the Tama-Go here on TamaTalk, so I thought it may be helpful if I wrote a complete list of what each figure unlocks once connected to the Tama-Go egg.
There are some slight differences between the figures because Bandai released them in 2 separate "waves", much the same as they did with the physical egg. The first wave of eggs was a green egg with Mametchi figure, blue egg with Memetchi and white egg with Kuchipatchi. The first wave of figures are shown in this photo below.
The second wave eggs were a black egg with Mametchi figure, purple egg with Memetchi, and pink egg with Kuchipatchi (the one I have).
The second wave of gotchi figures is shown below.
There are two kinds of gotchi figures that can be attached to the Tama-Go egg. "Lite" figures which are the figures that come packaged with the Tama-Go egg. The figure that came with the first wave, whether it be Mametchi, Memetchi or Kuchipatchi, only unlocked one game; Cradles. Each of the figures from the second wave unlocked coin catch.
The "full" figures, shown in the photos above, each unlock 2 games and a shop. The shops each have a total of 9 products on sale, but will only show 4 at a time. For some characters, such as Mametchi, the shop is a shop that sells items. As items weren't built into the original Tama-Go egg, the item menu is also accessed by the character icon in the top right of the Tama-Go egg's screen. The figures also come with an additional faceplate that can be placed under the clear plastic on the front of the Tama-Go egg to change its design.
Here's a list of all the "Full" gotchi figures and what they unlock.
Games: Hip Hop and Speed Runner
Shop: Toy Shop
Games: Hit a Note and Panel Match
Shop: Clothes Shop
Games: Flag Game and Vegetables
Shop: Chinese Restaurant
Games: Bounce Back and Man Hole
Shop: Flower Shop
Games: Monster Beater and Shape Sorter
Shop: Sweet Restaurant
Games: Panel Construction and Shuffle Shuffle
Shop: Toy Shop
Games: Trampoline and Farmkeeper
Shop: Mexican Restaurant
Games: Knock a Note and Candies
Shop: Bread Shop
Games: Hunting and Manhole
Shop: Fashion Shop
Games: Driving and Ball Match
Shop: Sports Shop
Games: Gap and Gap and Hip Hop
Shop: Electronics Shop
Games: Sound Block and Shuffle Shuffle
Shop: Travel Shop
Hopefully in the near future I'll be able to give you guys more information about each game and shop. I've only had the figures for a few days and I'm very busy with work. Hopefully this is informative but if you guys have any questions, comment them here or PM me.