It’s dead, Jim! No Bones you can’t bring this one back: Pokemon Rumble Rush seems completely lost to the ether.
Following a warning from The Pokemon Company recently, they made good on their word to kill off the ill-fated Rumble Rush mobile game, which was part of the Rumble series that started all the way back in 2009. As of today you cannot log into the game even if you own it as the servers are shut off entirely, nor can you download it out of curiosity: as it has been removed from the iOS marketplace.
Such is the danger of becoming invested in digital, especially so-called “live service” games. The Pokemon Company notes that you can’t even spend your premium currency (Poke Diamonds): so hopefully you saw all of the early warning signs and cashed out with as much fun as you could spare!
Pokémon Rumble Rush Service Ending [Pokemon]
Source: Destructoid Pokemon Rumble Rush is completely dead