What the entry needs is a form of differentiation that will allow both entries to be added. Since this one has a different release year than the existing entry, it can't be listed as a variation because technically it's not. Here's an example we've run into before:
JeopardyJeopardy 2001Jeopardy 2003Same needs to be done with yours. The original existing entry needs a page edit to add the year of release, then a new entry added with your info and the year in the title also. That way each entry can also have it's proper retail info.