Is this PCB beyond repair?

[gabriess]

I used alcohol to remove the green/blueish residue, thus it's likely that some water got inside. I notice that a few solder connections on the upper left chip—the chip on the opposite side—have entirely corroded away. Additionally, there is some erosion at the vias and on the contacts of the smaller chip on this side. I want to know if all of these surface mount connections need to be resoldered or if the damage is too great. (Note that when I connect the PCB in, it still accepts power correctly, but it no longer functions as it once did.)
I would also like to know if the round metallic object is an on-board battery.

A Niko Home Control Hub contains the PCB.

[Nellamitham]

If the copper is eroded too much, resoldering alone may not restore a reliable connection. You may need to use wire jumpers or reconstruct the pad traces.