Streets Of Rage Wiki

Particle and Molecule, collectively known as X-Robots, are the bosses of stage 7 from Streets of Rage 2, they are joined by Isotope and Uranium on harder difficulties. Palette swaps named Oxygen, Hydrogen, and Mercury appear as mini bosses at the beginning of the final stage.


These robots are incapable of walking, moving around the level by short hops and big jumps. The heads contain laser cannons that can shoot for long range attacks. When using the laser attack, the robots will kneel down to aim. Mid and close-range attacks consist of launching spiked balls on a tether towards the player. They also have an area attack where they spin the spiked balls around themselves; forcing the player to keep their distance.

If the player grabs one of the robots and hesitates, they will electrocute the player. Upon defeat, the robots explosively self-destruct, which will hurt players that stay too close.



  • It is not explained why they only hop despite being capable of walking (going by their joint design).
  • The fact that there are only a few of them suggests that they are expensive to produce (likely the reason why the P-Robots are developed as a cheaper but less powerful alternative to them).
  • A drawing of the X-Robot, alongside the P-Robot appears in one of the stained-glass windows on the last stage from Streets of Rage 4.
  • Mass produced X-Robots appear in one of the Factory stages in the Survival Mode for Streets of Rage 4.