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