Cleared all shooting levels and beat all custom levels deathless (separately)

No-Miss clear

Died at the very last level so I had to replay the totality of the run, rip. At least I got the theoretical best score

Done, as well as a bunch of easier challenges

Trying to do the random upgrades challenge on co-op (the second account being an alt). It's hard as fuck, mostly because you need to reach insanium and because I spent too much time not knowing how to buy revives.

Class of Twilight OL clear

After enough failed attempts, managed to get all humans on space station and master this game.
(Total playtime: 37h 42m)

After first practicing master ILs and getting smakced, then going through master and instandly dying due to the new hazards + me trying to get all humans and speedrunning...
Managed to get the Master+Hero 2ALL INCLUDING the TLB!
This was an absolute pain in the ass, many attempts.

Now I only have to collect all humans on space station and I'm done

Finally, 1CC of Arcade on Veteran without dying, INCLUDING the TLB with no hits.
Now on to master diff.

Did the deathless veteran 1CC, but also not really because I defeated the TLB while losing lives... which I shouldn't have defeated in the first place.

I also got all steam achievements at 17h 48m of playtime on this account thanks to feat grinding.

Cleared arcade on Veteran. 1CC is the new goal
(40m).
1CC'ed three times. Once while failing to grab 2 normal humans, another with all normal humans but lacking hidden ones, and the other including those. The latter unlocked the feat I was aiming to.
At this point the total playtime would be between 14-15 hours I guess.

Then I started to do deathless runs, died at the very last boss before TLB. :(
---------------------

Played the game, played the game. Cleared it on experienced on an alt account (not 1CC)
(1h 19m)
-----------------------------------
then went straight to veteran to grind it and learning all human and 1up locations in the process.

All achievements gotten. 3 hours for Cancer Speed, the rest of the time was spent grinding attempts in order to get powerful enough to... no-hit a specific boss.

Still missing wins with a few characters but that isn't an achievement.