When Ski Lifts Go Wrong is listed twice on the site:
https://completionator.com/Game/Details/37971
https://completionator.com/Game/Details/45704

Gintama Sumaho Battle Chronicle (https://completionator.com/Game/Details/81284) and Gintama: Gathering (https://completionator.com/Game/Details/81285) are both missing from the Gintama franchise.

I've ensured that everything so far has been updated, with a couple of exceptions. The Sims Legacy Collections will need to be updated manually by moho_00, as well as the duplicate of When Ski Lifts Go Wrong.

Art Academy: Home Studio (https://completionator.com/Game/Details/68377) is known as Art Academy: Atelier in PAL regions

Updated!

The following are missing from the Just Dance franchise:
Just Dance (https://www.completionator.com/Game/Details/2727)
Just Dance 2016: Gold Edition (https://www.completionator.com/Game/Details/22860)
Just Dance: Summer Party (https://www.completionator.com/Game/Details/2731)
Yo-kai Watch Dance: Just Dance Special Version (https://www.completionator.com/Game/Details/53142)

Would it be possible for a The Rising of the Shield Hero franchise to be created containing:
Picross: Records of the Shield Hero (https://www.completionator.com/Game/Details/81606)
The Rising of the Shield Hero : Relive The Animation (https://www.completionator.com/Game/Details/52489)
The Rising of the Shield Hero RERISE (https://www.completionator.com/Game/Details/81640)

Updated both franchises!

Some things to update in the Deca Sports/Sports Island/Deca Sporta franchise
Deca Sports 2 (https://www.completionator.com/Game/Details/18272) is known as Deca Sporta 2: Wii de Sports "10" Shumoku! in Japan and Sports Island 2 in PAL regions.
Deca Sports 3 (https://www.completionator.com/Game/Details/18274) is known as Deca Sporta 3: Wii de Sports "10" Shumoku! in Japan and Sports Island 3 in PAL regions.

Deca Sports DS (https://www.completionator.com/Game/Details/28548) does not show up when searching Sports Island for some reason.

Also is it possible to for a franchise of this series to be created containing:
Deca Sports (https://www.completionator.com/Game/Details/18273)
Deca Sports 2 (https://www.completionator.com/Game/Details/18272)
Deca Sports 3 (https://www.completionator.com/Game/Details/18274)
Deca Sports DS (https://www.completionator.com/Game/Details/28548)
Deca Sports Extreme (https://www.completionator.com/Game/Details/58511)
Deca Sports Freedom (https://www.completionator.com/Game/Details/50473)

It looks as though there is some work to be done adding info for the Deca Sports titles. I am going to have to commute to my place of employment but, as soon as I get back home from work, I will tackle all of this. Thanks for your attention regarding this matter.

EDIT: Added boxart for Deca Sports 2 & 3 and included Japanese and European titles for both. Also, all 6 games are linked to the Deca Sports franchise and have VGPC mapping.

Unfortunately, it appears that a search for "Sports Island" still doesn't show Deca Sports 2, Deca Sports 3, or Deca Sports DS entries despite the info having been added in. Hmmm..