Previous works have shown the potential of immersive technologies to make physical activities a more engaging experience. With encountered-type haptic feedback, users can perceive a more realistic sensation for exertion interaction in substitutions reality. Although substitutional reality has utilized physical environments, props, and devices to provide encountered-type haptic feedback, these cannot withstand the fierce force of humans and do not give feedback when users move around simultaneously, such as in combat sports. In this work, we present Hit Around, a substitutional moving robot for immersive and exertion interaction, in which the user can move and punch the virtual opponent and perceive encountered-type haptic feedback anywhere. We gathered insight into immersive exertion interaction from three exhibitions with iterative prototypes, then designed and implemented the hardware system and application. To understand the ability of mobility and weight loading, we conducted two technical evaluations and a laboratory experiment to validate the feasibility. Finally, a field deployment study explored the limitations and challenges of developing immersive exertion interaction with encountered-type haptics.