Really?
Last I checked Mario Parties 8 and DS were the best selling games of the series, by far.
The reason it declined, and is still declining is because Nintendo still refuses to get with the times and include the OBVIOUS thing for Mario Party, which is online multiplayer!
If they just did that one thing, sales and interest in the series would skyrocket!
Hardware Comparison Threads:
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Is Hardware Getting TOO Powerful?
Older Threads:
PlayStation/Xbox/Switch: 2022 Edition
PlayStation/Xbox/Switch Hardware Battle: 2021 Edition!
PlayStation 4/Xbox One/Nintendo Switch: 2019 vs. 2020
PlayStation 4/Xbox One/Nintendo Switch: 2018 vs. 2019
PlayStation 4/Xbox One/Nintendo Switch: 2017 vs. 2018
PlayStation 4: 2015 vs. 2016 vs. 2017