A spactacular start
You have a simple "every one can play" game but our job is not to make simple games you can make an awsome game. I might suggest additions like... maybe the web should act diffrently when you eat more flys full spider dose not clamb so well. In retrospect I did play on easy, I will give another try on hard etc. Also a lvl building mod would be nice.
perhaps you should theme the lvls like in the woods make tree/bush branches insted of random blocks, protruding bricks and statues etc.
another idea would be to mix up game play a little and make a boss. "omg a child with a stick run like the dickens!!!"
Or
Spidy race NPC spidy compeats for who gets flys first.
maybe a happy ending like... last lvl is in a mad scientest lab and you become super big and "mighty" spidy.
I would love to se a Mighty Spidey II or 2.0
keep up the good work.