Full list of all 28 Windowkill achievements.
The base game contains 22 achievements, and there is 1 DLC pack containing 6 achievements.
hold 8 stars at once
kill every boss
get a x4 multiplier
survive for 2 minutes without shooting the window as bastion
beat timed mode
collect a 1000+ value coin
kill 10 spikers
obliterate a star
get lv. 10 multishot
buy 100 shop items
get 40,000 coins in one run
have 50 health
survive for 20 minutes
kill ???
?
get lv. 4 halt
kill an orb array as zephyr
kill 98 bosses
manifest 50 items
beat timed mode as :)
unlock everything
survive for 4 minutes without collecting a coin
get lv. 4 detach
kill wyrm without causing a split
kill 2 bosses at once during halt
block 200 bullets
die to slime trail