Cool game! Searching for the target is hard as you're combining serial search (looking at each individual item and dismissing each distractor) with tunnel vision, which means you can't rely on peripheral vision for any sort of processing. I think having some sort of cue to aid the player will go a long way, as right now it's very hard to find the real target. Once you find it, it's obvious, but you don't want to lose too many players early on! Visual feedback on click would help, other cues would help (audio when you find the target for example)