Complete 30 "Most Wanted" missions and 20 "Vigilante" missions found in police vehicle computers. Quick References & Resources GTA 4 Guide - IGN
Win at least one game of pool, darts, and bowling, and beat the high score in the QUB3D arcade game.
Hunt down all 200 "Flying Rats" (pigeons) and complete all 50 stunt jumps.
Committing crimes in front of police immediately draws attention. If you are arrested, you lose all your current weapons; if killed, you only lose cash. Advancing the Story
Complete all main missions and specific side tasks like Little Jacob’s drug deliveries and Brucie’s exotic exports.
GTA IV features more realistic driving physics than its predecessors. Ease up on the gas during skids rather than making sharp turns. When riding motorcycles, waiting a few seconds before accelerating lets Niko put on a helmet, which reduces damage from crashes.
Some missions force you to choose between characters, which can impact your rewards. For instance, choosing between Derrick or Francis offers different monetary gains and perks. 100% Completion Checklist