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