Just do it with events. Give the robot three variables vx=0, vy=0, and gravityStrength=400. In the click event it shows how to set vx and vy from a speed of 200 and an angle of 45.
Global number gravityDir=0
for each robot
--- set gravityDir to angle(robot.x, robot.y, planet.x, planet.y)
--- robot: add self.gravityStrength*cos(gravityDir)*dt to vx
--- robot: add self.gravityStrength*sin(gravityDir)*dt to vy
--- robot: set postion to (self.x+self.vx*dt, self.y+self.vy*dt)
--- robot: set angle to angle(0,0,self.vx,self.vy)
on click
--- create robot at (player.x, player.y)
--- robot: set vx to 200*cos(45)
--- robot: set vy to 200*sin(45)