Korobeiniki is the 19th stage of Piano Tiles 2. It is unlocked when the player reaches Level 7. It is together with Fur Elise, Turkish March, Canon Rock and Chrismas Zoo the only song with Rapid Tiles and is also considered as the hardest rapid tile song due to the repetitiveness and speed required to tap the Rapid Tiles. The current world record is 5602 by Robis.
This song, while considered to be at moderate speed and difficulty, some players might experience problems completing 3 crowns on it.
It's also one of the songs that speed up noticeably.
Before 3-star Edit
Consider yourself tapping the Rapid Tiles with 2 fingers together instead of tapping with 2 fingers step-by-step rapidly. This should also reduce chance of losing. The other tiles are easy to complete.
Post 3-star Edit
Make sure your fingers aren't incapable of tapping at very fast speeds. This reduces chance of finger shaking.