Here is the full list of all 48 Sonic Forces achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Collected all parts
Collected all Wispons
Achieved highest honors with all races
Completed all Challenge Missions
Collected a total of 100,000 rings. (All Rings held at the end of the stage will be counted.)
Collected a total of 50,000 rings. (All Rings held at the end of the stage will be counted.)
Collected all Silver Moon Rings in Shadow's Story.
Collected all Number Rings in Shadow's Story.
Collected all Red Star Rings in Shadow's Story.
Created your second Avatar
Cleared all EX Stages
Collected all Silver Moon Rings
Collected all Number Rings
Collected all Red Star Rings
Collected 30 Wispons
Restored peace to the world
Defeated 10,000 enemies
Collected 500 parts
Cleared all Secret Stages
Defeated Infinite
Turned the tide of the conflict
Completed 10 SOS Missions
Completed 10 Daily Missions
Equipped a part in every slot
Drove off Infinite again
Liberated a world
Defeated 5,000 enemies
Completed 5 SOS Missions
Collected 10 Wispons
Drove off Eggman
Collected a total of 10,000 rings. (All Rings held at the end of the stage will be counted.)
Achieved a soldier's highest honor
Completed your first SOS Mission
Collected 100 parts
Completed 5 Daily Missions
Drove off Infinite
Collected 50 parts
Defeated Zavok
Collected Silver Moon Rings three times
Collected Number Rings three times
Defeated 1,000 enemies
Changed Wispons for the first time
Used the Closet
Completed 3 Daily Missions
Utilized the Rental Avatar function
Made it into the rankings
Created an Avatar
Cleared Stage 1