Kelsey

Kelsey is a boss which many new players struggle with. This is primarily due to the lack of information on dealing with her clones when she reaches her 35% HP Marker.

At her 35% HP Marker, Kelsey will summon 4 clones (3 phonies + 1 "real" one). The fake clones can be identified through purple smoke emitted from them (see bottom image). Hitting the fake clones will cause you to lose 1 HP. As such, newer players should not rush to attack her clones, but to observe the clones carefully whilst dodging her Spike and Projectile attacks before concluding which of the four Kelseys is the "real" one.

Alternatively, players may opt to completely ignore her clones and focus only on dodging her attacks. However, this will result in them losing a minimum of 2 HP.

Pro Tip: Set the Game's Detail level to "Very Low" to prevent the Swamp background from being displayed. The background will instead be replaced with a solid gray-ish one instead, making it easy to see the purple smoke emitted from the fake clones.