Here is the full list of all 48 Lil' Guardsman achievements worth 1,000 gamerscore.
Completed Level 2
You achieved a perfect 4-star average in level 2!
You encountered the first of many landmines in Lil' Guardsman. Good job!
Completed Level 3
You achieved a perfect 4-star average in level 3!
You heard Lil say triple barf to a visiting head of state!
You vaporized goblinball legend Saruna Goodfoot!
Completed Level 4
You achieved a perfect 4-star average in level 4!
Chose the mage Articulus Flamehands to rescue the princess
Chose the warrior Neil Warkiller to rescue the princess
Chose the thief Perry Shoutson to rescue the princess
You are either very smart or very lucky: all of the contestants survived!
You encouraged Beverley to embark upon a perilous quest!
Completed Level 5
You achieved a perfect 4-star average in level 5!
You helped convince the princess to choose Finius and ally with Petrard
You helped convince the princess to choose Kargan and ally with Marvagh
Completed Level 6
You achieved a perfect 4-star average in level 6!
Planned a perfect Petrardian party!
Manifested a magnificent Marvagh matrimony!
Completed Level 7
You found the birthday girl and gave her a present! Whoo!
Witness the entire wedding ceremony without objecting
Completed Level 8
You achieved a perfect 4-star average in level 8!
Your draft choices led to victory in the land battle!
Completed Level 9!
You achieved a perfect 4-star average in level 9!
Your draft choices led to victory in the aerial battle!
Your incessant calls to Malcolm led to a terrible curse taking hold. Quack!
Completed Level 10!
You achieved a perfect 4-star average in level 10!
You were visited by the ghost King Oswin! And heard some Shakespeare!
Completed Level 11!
You achieved a perfect 4-star average in level 11!
Your actions led to Gary turning to the dark side
Your actions prevented Gary from turning to the dark side
Your draft choices led to victory in the naval battle!
Your draft choices led to victory in the every battle!
Your choices led to hearing Tyronius' speech involving smaggle slaves
Your choices led to hearing Tyronius' speech involving Petrardian forces taking the digsite
Your choices led to hearing Tyronius' speech about economics. WTF?
Your choices led to hearing Tyronius' speech blaming you for all the terrible things that happened!
You defeated Tyronius before he could use the chronometer once! (Is this your second playthrough?)
Your choices have led to the best ending, with the Sprawl repelling the invading army!
Your choices have led to the second best ending, with the Sprawl failing to repel the invading army