Even if you could somehow fit the engine, you'd face insurmountable challenges with:
* Transmission: The Talon's transmission won't bolt up to the Saturn's differential.
* Mounts: Engine mounts would need to be completely custom fabricated.
* Wiring Harness: The electrical systems are completely incompatible.
* Computer/ECU: The Talon's engine management system would not work with the Saturn's systems. A standalone ECU would be required, adding significant complexity and cost.
* Driveshaft: The driveshaft would need to be custom made.
* Exhaust System: A whole new exhaust system would be required.
* Cooling System: The cooling system would likely need significant modification.
In short, while technically *nothing* is impossible with enough time and money, this engine swap is highly impractical and would be far more expensive than buying a different car. The cost and effort involved would far outweigh any potential benefit.