GAME OVER !!
but that video i can hear 2 sounds, the sound of a lifter TICK and the sound of a rod KNOCK....those get confused all the time, one mans tick and another mans knock
KNOCK are deeper and in the lower end, TICKS are in the top of the motor and not so deep big hammer smashing sound lol
LIFTER TICK (not much to worry about, maybe just use thicker oil or marvil mystery oil, most 2.2 ohvs do this in old age, mine right now does it but not as loud)
ROD KNOCK (basically game over, the motor will sieze up sometime depending on how you drive it....most you'll get is a few months easy driving, maybe little more, maye little less)
Hope that helps =)
lifters may get louder when you rev it, but the other engine/road/exhaust noise should make it seem quieter, listen to the second video, how deep it sounds and how it sounds when he revs
if your still not entirely sure, get a long screwdriver and place its tip on the head and you can listen through the end, move it up and down the head and the sound will get louder in the area of problem. Best is if you get your hands on an automotive stethescope, similar principle but far more accurate.
My motor deff sounds like the one in the second video...its in my race car so it will be beaten the balls off of