SiNiSistar 2 All Achievements Guide — Steam Deck

SiNiSistar 2 has 26 Steam achievements, and the large majority are automatic story rewards for defeating each boss. The ones that trip people up are the handful tied to optional rooms, alternate kill conditions and the hidden boss Seere. This page lists all 26 with their rarity so you can see at a glance which ones need planning.

How many achievements does SiNiSistar 2 have?

The game ships with 26 achievements worth 2,528 obtainable points on the tracker used for these figures. Completion data at the time of capture showed 174 players with the full set against 590 tracked players. Rarity is a useful planning tool here: anything below about 50 percent marks a fight or condition that most players did not finish, which usually means it is optional or easy to miss.

Full achievement list with rarity

Achievement	Requirement	Rarity
Penetrating Arrow Magic	Learn the piercing arrow ability	74.92%
Exploding Arrow Magic	Learn the exploding arrow ability	58.14%
Owl Magic	Learn the gliding ability	45.93%
1 Shot 3 Kills	Defeat 3 or more enemies with one piercing arrow	60.85%
Staurotheca	Find the Staurotheca	41.19%
Abomination Broodling Nanny	Defeat the tutorial boss	99.49%
Gravekeeper	Defeat Gravekeeper	75.08%
Enenuth Mother	Defeat Enenuth Mother	59.32%
Backstab	Defeat Enenuth Mother from behind	30.00%
Swamp Abomination Broodling	Defeat the swamp boss	71.69%
Demihuman Abomination Broodling	Defeat the lair boss	65.59%
Demihuman Remnants Leaders	Defeat the remnants leaders	64.07%
Dreamwood Tree	Defeat the Dreamwood Tree	68.98%
Abomination Broodling Harbinger	Defeat the harbinger	66.78%
Pigman	Defeat Pigman	65.93%
Imitation Abomination Broodlings	Defeat the imitation cluster	56.27%
Stomach Abomination Broodling	Defeat the Innard Cave boss	56.27%
Giant Spider's Cocoon	Defeat the spider cocoon	67.80%
Skull Staff Priest	Defeat the skull staff priest	52.20%
Hag	Defeat Hag	57.29%
Eye Priest	Defeat the eye priest	52.71%
Nightmare Painting	Defeat the Nightmare Painting	51.02%
Giant Pig	Defeat the giant pig	51.69%
Brain Snail Cluster	Defeat the brain snail cluster	51.19%
Otherworlder	Defeat the final boss	48.64%
Seere	Defeat the hidden boss Seere	41.19%

Which achievements are missable

Three of the 26 depend on choices or conditions rather than simple progress, and one of those can be locked out for a whole run. Backstab is the strictest: if you defeat Enenuth Mother normally before taking the surprise attack from behind, you need New Game Plus to try again. Staurotheca is less punishing, but the item sits under the library elevator and is easy to walk past. Seere requires Scivias Powder, so it is only available once Act 3 opens.

The magic achievements are technically missable too, but only if you skip the rooms that grant them. Owl Magic comes from an optional destructible wall in the Demihuman Lair, and the explosive arrow is earned in the northeast village. If you are aiming for a full set, treat all three optional pickups as mandatory and check the SiNiSistar 2 hidden achievements page for the exact conditions.