OK, my friend thought of this: wouldn't it be cool if, when a coconut fell, if the spider was under it, it would squash the spider and stop the coconut? Wouldn't that be awesome!
I have to admit I've wasted a good bit of time trying this theory! I've also tried pressing the down key to "block" the coconuts from hurting me and avoiding the spiders.
Trust me newcomers: stick to jumping over the spiders and avoiding the coconuts!