Here is the full list of all 40 I Hate Running Backwards achievements worth 1,000 gamerscore.
Collect 666 souls
Finish a loop without receiving damage
Kill Ugh Zan without taking any damage
Kill Biomechanoid while four curses are active
Kill 10 RoadBulls on the Road ground
Finish a game loop
Kill the second form of Ugh Zan
Kill Ugh Zhan
Knockback 100 enemies
Gather 50k chunks from destruction
Deflect 500 projectiles
Destroy 30 mines while invulnerable
Destroy 50 watchtowers
Kill the Biomechanoid without being hit
Kill 1000 enemies with a hammer
Destroy a special crystal in Crystal cave
Destroy a secret trash container
Kill the werebull
Deflect 50 cannonballs
Unlock 15 special weapons
Use ultimate ability 5 times in the same run
Kill Biomechanoid boss
Kill the Lava golem
Kill Scrapjack using only the hammer
Kill King Scorpion before he burrows
Kill King Scorpion while two curses are active
Heal for 20 health during one session
Get to King Scorpion using only the hammer
Gather 5k Mojo from destruction
Deflect 20 rockets
Kill Scrapjack
Kill King Scorpion
Collect every powerup in one run
Die!
Get the combo counter to x50
Destroy a weapon crate
Detonate 50 Explosive traps
Finish a loop with all 6 curses active
Finish a loop without receiving damage with 6 curses active
Freeze 100 enemies