The current code never resets the vertical velocity, leading to it accumulating over time and every subsequent fall starting at the previously set velocity.

It would likely be preferable to simply mutate the vertical component based on the body's experienced velocity _targetVelocity.Y = Velocity.Y - ..., however, this co-dependence between _targetVelocity and Velocity might make the functionality harder to understand and may therefore be less beneficial for didactic reasons.