Certainly doable but to get great SFX you need a good speaker and an amplifier. Not sure how much room there will be in your gun.
If you look at the picture that shows the bottom of that player, the pins are labeled. Actually there are just holes for pins, you can solder pins into them or solder your wires directly into the holes. You can direct control up to 8 different sound files with switches or buttons. The direct control pins are active low, which means when any of them are touched to GND, it will play the corresponding file. It can only play one file at a time but it doesn't have to finish one file to play another. If it's in the middle of playing one file and you trigger another pin, it will play that file. Your files have to be renamed 1001.MP3, 1002.MP3, and so on up to 1008.MP3 (files 1-8). BTW, it also plays WAV files. Here's the link to the data sheet for that player. http://mdfly.net/Download/Module/AU5016.pdfI already ordered the J-man suggested piece, but then did a bunch of reading on the website suggested by Jeff. I'm kind of getting an idea on how these work now and will probably be able to piece together something.
I see these aren't polyphonic, but that's fine. I was thinking of having the gun have three switches, each one would be some kind of a rising tone, and they would indicate 'power levels'. when the third switch is pulled, then it can be fired with the trigger.
Thank you both J-Man and Jeff, these little boards are very much what i was looking for! Push button sounds that i can create!
J-man, I was wondering about that and I'm glad that is the behavior ir performs. I was hoping I didn't have to wait for one sound to finish before the next plays. This way i can 'rapid fire' and it will just shoot again. By the way, this will be more of a 'pew-pew' gun rather than a 'bang bang' gun. Thanks also for the data sheet.It can only play one file at a time but it doesn't have to finish one file to play another. If it's in the middle of playing one file and you trigger another pin, it will play that file.