just cuz i want you people to know, DO NOT BLOW IN YOUR NES CARTRIGES!!!!!
your breath is sort of humid, so it you blow in an NES cart, moisture gets on the cart's chip and gets in beetween your game and your 72-pin or toploader thing. over time this can corrode your contacts and make the game worse! i would know, because i used to use a moist toothbrush on my games to make them work! then some 3 years after i started doing that i got the brains to look on the internet how to fix it, luckly my nes works now.