Don't get attached to your save games! Each time there is a new update to the game (especially one that adds a new stage), it will require a save game reset which will be handled automatically. This isn't because I'm too lazy to program a save compatibility system, but rather because each update contains so many tweaks to gameplay and various pre-existing stages that it's unfair to allow existing saves to finish and place on the Leaderboards having already gone through a portion of the game.
But it'll be worth it! The new stage is great fun. It's called Snowy Slope Volcano. Think Snowy Snowy Mountain in Super Mario 64, but with traps and no penguin.