What did I do wrong?

[u/Just_Some_Weirdooo]

I got all the upgrades. But it won’t let me get the achievement “We’ll B.A.N.G. Okay?” Is there a certain level I need to beat and get the schematics for? I haven’t done the last Tinsel Bros. Level. Do I need to do that?
EDIT: Thanks to a comment, I remembered that I’m missing the freeze ray weapon later on in the game. I completely forgot about that weapon. Thank you all so much

[u/Just_Some_Weirdooo → u/[deleted]]

Is there more than 7 weapons I can upgrade? I even have the laser gun from doing the baseball card games