Nuts 'n' Bolts is the 1st stage of Techneurosis. Next stage: Space is the Place.
Metal Cyclone (77,777 HP, 77,000 damage, 10 knockbacks) with Super Metal Hippoe and waves of Metal Doges — a Metal wall where only Critical Hits count.
- Spam Catasaurus and Showoff Cat: the Showoff stack keeps Metal Cyclone frozen while the Catasauruses land the crits that finish it.
- Without Catasaurus, Hurricat plus one other Critter does the job.
- Keep the remaining slots for the Continuation stage, Space is the Place — this one needs only a few.
Similarly to other Cyclones, this very slow enemy attacks non-stop and deals extreme damage, but has a tiny range of 65. It takes only 1 damage from non-Critical attacks like all Metal enemies yet has more than triple the health of Sir Metal Seal, requiring a lot of Critical Hits to defeat.
SHOWOFF CAT B An incredibly efficient way to beat this level is to spam Catasauruses and Showoff Cats; the large amount of Showoff Cats should constantly freeze Metal Cyclone while the Catasauruses keep doing Critical Hits and finish off Metal Cyclone. 
CATASAURUS A An incredibly efficient way to beat this level is to spam Catasauruses and Showoff Cats; the large amount of Showoff Cats should constantly freeze Metal Cyclone while the Catasauruses keep doing Critical Hits and finish off Metal Cyclone. 
HURRICAT A If you don't have Catasaurus, you can replace it with Hurricat and optionally one other Critter. Metal Cyclone is Metal — normal hits do 1 damage; only Critical or Toxic damage gets through.
Critical is a chance, not a guarantee — lead with 100%-crit or Toxic units; low-crit ones are slow backups.
CRAZED MONEKO A Reliable Critical hits punch through Metal. 
GLASS CAT A Toxic damage ignores Metal armour. 
CHEERLEADER CAT A Reliable Critical hits punch through Metal. Also fits “Out-range Metal Cyclone.” 
TECOLUGA S Reliable Critical hits punch through Metal. Also fits “Out-range Metal Cyclone.” 
HIGH LORD BABEL S Toxic damage ignores Metal armour. 
BRAINWASHED FISH CAT A Toxic damage ignores Metal armour. 
⚙ More counters worked out from the roster, lower confidence than the picks above; kept for reference
Metal Cyclone reaches 65 range. Units that out-range it can chip safely without taking hits.
GROSS CAT A Range 350 — fires from beyond its 65. 
MASTER URIL A Range 405 — fires from beyond its 65. 
AKU RESEARCHER A Range 400 — fires from beyond its 65. Also fits “Crack the Metal.” 
BACKHOE CAT A Range 350 — fires from beyond its 65. Also fits “Crack the Metal.” 
CAT CLAN HEROES S Range 350 — fires from beyond its 65. Also fits “Crack the Metal.” 
The castle you destroy to clear the stage.