They still run on Hive. The rewards after winning is either potion, DEC, Credit or Cards which actually from Hive Engine.

But, Splinterlands just giving options to players to connect with Hive or not.

This is good, so that new players can focus on only playing games without having to post on Hive.

Anyway, Splinterlands do have their own blog platform, Splintertalk which rewards token, SPT