Adding sound and music to a game really transforms it. I like to leave sound till the very end. Cause once you take a huge game and add sound and music, all of a sudden it comes to life and feels really immersive. I'm not the greatest with sound effects, I usually cut them together fairly quick. So I'll share some great sound effect and music websites I use.
Worth noting is you will have to download an audio editor, some sound effects need a little chopping at the start and end or maybe make the volume louder. This will expand the amount of sound effects you can use that you find online if you are willing to edit them yourself. A great free audio editor is Audacity, I recommend downloading it.
Huge downloadable packs of sounds for free. These are more movie effects, but work very well in games. Remember with sound you can take a completely different sound effect and make it work for something else with some clever editing. The mind tricks the ear by using visual stimulation to make the sound more fitting with what they see.
Mixed feelings about this site, they used to be free and the best sound on the net, but now you have to pay. Not sure if they still offer 5 free sounds a month or got rid of it. A good option anyways if you're willing to pay for some top notch sound effects by famous sound producers.
One of my favourite, they have a lot of real sound effects if your looking for something less cartoony. Huge list of sounds as well.
Good for simple effects in a pinch or starting out. I'm not a huge fan of this resource due to the quality being a lot lower than the other links, but with sound effects sometimes you needa search multiple places looking for that right one.
My favourite place for getting music for my games. It's made by other indie developers so when you submit your game you can link the track back to there profile to show support which is a great idea for uniting sound artists together with flash artists.
The website Stormgardens.com did an interview of me recently. So it's good to get more exposure. That brings my total interviews to 2! woohoo. Anyways this a great flash website, it offers a unique option to advertise your own stuff on the frontpage by bidding storm points. You get storm points the more views your flash's get. A nifty idea and I hope it takes off.
Check out the interview here -
Look at some time in our lives we've got to ask ourselves what do we do in the catapocalypse!!?! It's coming. It's real. Zombie cats will rule the earth one day. You've got to be prepared. So I made this game engine where you can kill the zombie cats. Don't worry cat lovers, they're not cute cats. They are ZOMBIE CATS. So when you run upwards and grab the blender then go back out the house and blend the cats don't feel bad at all! Yes you can blend them, all is fair in cat war.
Sometimes I'm amazed at what ridiculous engines I make that don't go anywhere. Funny though.
Play the engine below. Arrow keys to move. Space to kick or to use blender. E to pickup blender.
A great option I recommend is in game ads. I usually put them on the preloader I've found they are not intrusive here and once the game starts there is no in game ads to annoy people. I'm not a fan of inter level ads, I don't like to ruin games as I've seen others do by annoying the player. Though some games are an exception when they have put the ad to the side of an inventory and it isn't in the way. Smart design is the key here.
My favourite is probably CPMstar, they offer an easy API and quick approval by a sponsor. The catch is you have to share 50% revenue with your sponsor but that is very fair if you make a good deal with them and it helps your sponsor trust you more for future sponsorships. So ads can benefit the developer and the sponsor as well.
With CPMstar it really varies on how well a game is doing. I usually make about $10-20 a month off them on average with 4 games using CPMstar. Sometimes I've gotten $50 when a game did well like Heli vs Tower. I figure the more games I release the higher this will get per month.
Mochi offer higher click through rates then cpmstar however you can only withdraw your money when it reaches $100. Mines been stuck at $50 for ages, it's frustating, but if you have more games with it can be good, specially if you're starting out and don't have a backing sponsor. They are overall good but still needs improving.
Newgrounds offers there own in game ads now. It's not as good as the other two above though. The click through rate is a lot lower and the ad sometimes doesn't display anything but the NG logo. However they are a good quick option with easy API if you want to support a side version of ads with a website that isn't fully based on it. Plus it adds up with your in website revenue. I released one game with it as a test, the game didn't do well, it's made about $100 from these ads in a few years.