Well, I think folks can remember what you create...as long as you give them some significant use in the story.
If you just give them passing mentions, and don't give them much use before just belting out more, then yeah, they'll fade into obscurity. But if you make use of them, and maybe give us time to see what awesome things they can each do, then not only will they be better appreciated, we'll be more likely to remember at least a few, as well as eagerly anticipating any new ones you put forth.
In my humble opinion.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)