When I was a teen, about 10 years ago, I remember having an iOS game where you played as a humanoid robot and the goal was to reach a cryogenically frozen woman (or perhaps a child?) guarded by waves of hostile robots.
It made a strong impression on me because of its apocalyptic setting, the main level (I believe there was only one) was set in a dilipdated urban area in a future where humanity had gone extinct, I think the lore implied it to be from global warming. The woman/child you were trying to save was the last human on earth. The graphics were fully 3D, I played it on an iPad and remember being impressed at the time. I'm 90% sure it was not f2p.
Gameplay was akin to a 2.5D cover shooter, you had to tap to move your character from wall to wall, shoot/duck with the right timing, and jump to avoid AoE beam attacks from some enemies, until you cleared that screen of enemies and were allowed to advance to the next in a cutscene. I recall the ability to equip and modify multiple arms, each with different abilities which could be upgraded. One of those arms was called "sucker punch", or something to that effect.
I think a core mechanic of the game was the theme of repetition and scaling difficulty, you couldn't actually win, every time you made it to the end and killed the final boss (a tanky robot) the game got slightly harder, and I think there were different ending cutscenes, but it was implied you were stuck in a time loop and couldn't actually save the person you were trying to save.
There was a sequel with multiple levels, I recall there being one in a moving train and another in an oil refinery or platform.
