Here is the full list of all 105 Spyro Reignited Trilogy achievements. It takes around 30-35 hours to unlock all of the achievements on Windows.
Bugbot Factory: As Sparx, defeat the Metapede
Starfish Reef: As Sparx, defeat the Manta Ray
Spider Town: As Sparx, defeat the Spider King
Country Speedway: Fire 5 missiles in one race
Mushroom Speedway: Fly Through 4 Star Speed Boosts In One Lap
Crawdad Farm: Defeat the Crawdad King
Midnight Mountain: Get revenge on Moneybags
Sorceress's Lair: Defeat The Sorceress
Dino Mines: As Agent 9, defeat an enemy with a ricochet shot
Harbor Speedway: Find Hunter
Haunted Tomb: Destroy All Sarcophagi
Desert Ruins: Find both butterfly jars
Crystal Islands: Defeat all the Crystal Bears
Agent 9's Lab: As Agent 9, shoot down all the balloons
Midnight Mountain: Free Agent 9
Scorch's Pit: Defeat Scorch
Evening Lake: Launch the Transporter Rocket
Honey Speedway: Fly through 12 star speed boosts in one race
Frozen Altars: Use ice breath to freeze 12 enemies
Lost Fleet: Use cannons to shoot down all vultures
Charmed Ridge: Defeat a giant
Fireworks Factory: Defeat Twin Dragons (Boss)
Bamboo Terrace: Follow the question mark bottles to the end
Bentley's Outpost: As Bentley, destroy all the totem poles
Evening Lake: Free Bentley the Yeti
Spike's Arena: Defeat Spike
Midday Gardens: Launch the Transporter Whirligig
Spooky Swamp: Defeat Sleepyhead
Icy Peak: Destroy 6 icy things using the cannons
Enchanted Towers: Destroy all the balloons
Sgt. Byrd's Base: As Sgt. Byrd, bomb all treasure chests
Midday Gardens: Free Sgt. James Byrd
Buzz's Dungeon: Defeat Buzz
Sunrise Spring: Launch the Transporter Balloon
Seashell Shore: Defeat Bluto's nuclear shark submarine
Molten Crater: Unlock the locked treasure chest
Cloud Spires: Glide for 5+ seconds (and land safely!)
Sheila's Alp: As Sheila, destroy all headbash treasure chests
Sunny Villa: Defeat all Coward Rhynocs
Sunrise Spring: Free Sheila the Kangaroo
Unlock the permanent Super Flame
Use all 3 types of power-ups in Ripto's Arena
Don't get hit by Bob
Defeat every Robo Bee by spitting
Defeat the Ox without taking a hit
Don't hit any Sheep in Cloud Temples
Charge through every Monkey in Mystic Marsh
Headbash every rock in Winter Tundra
Defeat 5 Buggies while charging
Complete the long glide to Orb in Autumn Plains
Defeat the Snowmobiles before defeating a Hang Glider
Defeat every Earthshaper in Fracture Hills
Complete Gulp's Overlook without harming fodder
Don't touch the hazardous water in Shady Oasis
Steal a Popcorn Crystal from Hunter
Flame the Pigeons first in Metro Speedway
Use a cannon to defeat a TNT thrower
Clean run in the trolley
Defeat all Draclets in one Superflight
Don't touch the lava in Skelos Badlands
Headbutt every turtle in Turtle Soup challenges
Light 6 Gem Lamps in 15 seconds
Complete Crush's Dungeon without hitting any fodder
Destroy every Roboshark
Heat up the audience
Charge a Goat in Colossus
Do not feed the Hungry Idol any red fish
Defeat every robot in Hurricos
Complete Hunter's challenge
Get Gnasty Gnorc to complete 5 laps
Collect all gems in Gnasty's Loot
Unlock Gnasty's Loot
Destroy 6 gears in Twilight Harbor
Complete Gnorc Cove without killing any Rats
Defeat 4 Nightmare Beasts in one glide
Complete Icy Flight without touching the ground
Charge through 4 Puffer Birds in a row
Defeat 3 Demon Dogs in large form
Defeat all Tin Soldiers
Charge through 3 Armored Fools in a row
Defeat Toasty without getting hit by him
Complete Wild Flight without touching the ground
Free a trapped Chicken
Light 3 fireworks within 15 seconds
Jump off every Supercharge ramp in Tree Tops
Collect 500 gems in Metalhead
Flame 5 Glowing Mushrooms in Beast Makers
Flame all Fairies in Crystal Flight
Detonate 3 explosive chests on the pillars in Alpine Ridge
Defeat all Metalback Spiders
Collect 400 gems in Blowhard
Charge through 4 Armored Druids near the start of Magic Crafters
Defeat hidden Egg Thief in Wizard Peak
Charge a Vulture
Flame all Fairies in Night Flight
Flame every Vulture in Cliff Town
Defeat all three Ski Gnorcs
Unlock the strong chest in Doctor Shemp
Do a loop around an arch
Use a cannon to dispatch a taunting Gnorc
Flame 10 sheep in Stone Hill
Take a trip with a Balloonist
Light the two bonfires in Dark Hollow
Glide to secret Egg Thief area in Town Square
Find the hidden entrance to Sunny Flight