since you have
CONFIG PBADEN = OFF ; PORTB<5:0> pins are configured as digital I/O on Reset



Code:
;Reset:  probably not a good name for a label
startup:

  OSCCON = %01010000             ' 4MHz 
 ;ADCON1 = 15                    what ?
ansela=0

;TRISB = %00000001              ' sets pin as input (1) or output (0)   ???????????????  
; TRISC = %10001100             ' sets pin as input (1) or output (0)  ?  for what reason
TRISB = %11111100 
TRISA = %11111100

  PORTA =0  
  PORTB =0  ' sets outputs as high (1) or low (0)
  PORTC = %00000000              ' sets outputs as high (1) or low (0) why ?


' -----[ Variables ]------------------------------------------------------------
 
    led1          var   porta.1  ' LED 1
    led2          var   porta.2  ' LED 2
    led3          var   portb.1  ' LED 3
    led4          var   portb.2  ' LED 4

action:
      
    led1 = 1
    pause 500

    led2 = 1
    pause 500

    led3 = 1
    pause 500

    led4 = 1
    pause 5000

while 1  ; loop forever