Originally only available as DSiWare, the game finally made its eShop debut.
http://www.nintendoworldreport.com/news/28857
DSiWare game, Pinball Pulse, finally made its way to the 3DS eShop.
Pinball Pulse: The Ancients Beckon was originally a DSiWare game that was unavailable on the 3DS at the eShop's launch. If you now search the eShop for the game, you can find and download the title for $4.99.
If you originally downloaded the title on your DSi, you can now transfer it over to your 3DS.