Game modes

=Difficulties= The player sets a difficulty every time she starts a new game or loads a save.

Relaxed Mode
The player cannot lose health or breath, but Tweaks can still break. Robin can die only if she gets crushed by the Omega Controller or runs out of air at Midway.

Standard Mode
This mode is normal gameplay. The player can lose health and breath.

Harder Mode
Many bosses become harder, often by having more health and shooting more fireballs during their attacks.

Challenge Mode
Challenge Mode is unlocked when the player completes a game for the first time. Robin dies whenever she takes damage, but not when breaking an Iron Heart or fighting Nobel. Tweaks are repaired by interacting with Icons of Prayer and beds instead of collecting Ivory squares. Bosses behave the same as they do in Harder Mode. Completing the game using only Challenge Mode unlocks One-Hit Wonder.

=New Game += Whenever the player completes a game, she can save a New Game + file, which copies all materials, Tweaks, and schematics from the completed game. Robin can equip Tweaks without meeting the ChemiCo Contra member, and her home contains a Tweak Crafting Table. Robin can reclaim schematics that she already received, but they will be purple instead of orange and not unlock Tweaks.

=Boss Rush= Boss Rush is unlocked when the player completes a game for the first time. All bosses behave the same as they do in Harder Mode. Robin has the Galvanization Wrench and all three shots. The player also gets three Iron Hearts in every difficulty except Lethal Rush. Bosses still drop Ivory squares and repair broken Tweaks, but lost health cannot heal.

Light Rush
This difficulty features Spine Controller (phase 1), Kerthunk, General Chrome (phase 2), Inti, Silver Watchman (phase 2), Gerrie, Agent Black (phase 1), and Ivory Beast (both phases).

Heavy Rush
This difficulty features Kibuka, Spine Controller (phase 2), Possessed Thunk, Blocker, Carver, Mendeleev, Agent Black (phase 2), Mother, Starworm, and Birdman.

Full Rush
This difficulty features Spine Controller (phase 1), Kerthunk, Kibuka, General Chrome (phase 2), Inti, Gerrie, Spine Controller (phase 2), Silver Watchman (phase 2), Possessed Thunk, Blocker, Agent Black (phase 1), Mother, Mendeleev, Agent Black (phase 2), Ivory Beast (both phases), Starworm, and Birdman.

Lethal Rush
This difficulty features the same bosses as Full Rush, but the player does not get any Tweaks.

=Trivia=
 * Completing Iconoclasts using only Challenge Mode and no Tweaks changes the artwork that displays after the end credits.
 * If the player holds left when entering Kibuka's room in a Boss Rush, Robin leaves the room. She can then save the game or explore most of the world.