Your MekaMon may be limping due to low battery power. In this case we would suggest recharging the battery and trying again.
Your MekaMon may also be limping due to a poorly connected leg. Underneath the MekaMon you will find leg release buttons. To remove a leg, press the leg release button and pull the leg from the body. Once unattached, simply reattach the leg by pushing firmly until an audible click is heard.