The game is simple and not new. The graphics are not extraordinary but I think the concept of the blood vessels has some potential for this type of game. We could control a blood cell for instance, or even the blood itself, like you could make an animation of the blood filling all the path as we go through it.
Also, the game has a common bug for this type of game. If we click, we can drag the cursor to the end and skip the level in a second. You can avoid this by displaying the gameover screen when the player clicks for example.
Having all that in mind, I think we can expect an interesting HeArT 3 haha