Achievements - don't load terms with your own biases! If you don't do that then it's always very easy to answer questions. Try and be objective.
It still basically asks "what did he do" in terms of say industrialising and modernising the country.
So:
- Industrialisation
- Collectivisation
- 5 year plans (and how did "Five in Four!" and other propaganda help?)
- Extensive use of labour/Mobilisation of resources
- Secret police (and other control aparatus to achieve these changes)
- Mobilisation of resources for WWII
- Foreign policy: USA, Ribbentrop-Molotov Pact, Russo-Japanese Anti-Aggression Pact
- The Great Patriotic War
- Strong, centralised leadership (necessary during the war or in huge building projects)
- Prestige projects e.g. various heavy industry and dams built as well as Turkish Railway