Trying to interface a simple push button with PIC12F675 controller in Proteus, but not getting output
Pins are in analog mode after reset. Set them all to digital mode like this: 

ANSEL &amp;= ~0x0F;
CMCON = 0x07;


See datasheet chapter GPIO PORT for more details.

Additionally, you have watchdog enabled. You either need to feed it regularly or disable it be setting # pragma config WDTE = OFF