The game uses 23 sounds effects, let's have a look at them with Audacity.
- sample1.wav: 8,000 Hz 9,250 bytes 8 bits
- sample2.wav: 11,025 Hz 10,803 bytes 8 bits
- sample3.wav: 11,025 Hz 9,257 bytes 8 bits
- sample4.wav: 11,025 Hz 2,192 bytes 8 bits
- sample5.wav: 22,050 Hz 31,364 bytes 16bits
- sample6.wav: 11,025 Hz 7,834 bytes 8 bits
- sample7.wav: 11,025 Hz 6,807 bytes 8 bits
- sample8.wav: 11,025 Hz 4,442 bytes 8 bits
- sample9.wav: 11,025 Hz 7,436 bytes 8 bits
- sample10.wav: 11,025 Hz 4,535 bytes 8 bits
- sample11.wav: 11,025 Hz 6,834 bytes 8 bits
- sample12.wav: 22,050 Hz 14,040 bytes 8 bits
- sample13.wav: 11,025 Hz 6,925 bytes 8 bits
- sample14.wav: 11,025 Hz 17,407 bytes 8 bits
- sample15.wav: 11,025 Hz 1,922 bytes 8 bits
- sample16.wav: 11,025 Hz 5,409 bytes 8 bits
- sample17.wav: 11,025 Hz 3,288 bytes 8 bits
- sample18.wav: 8,000 Hz 14,460 bytes 8 bits
- sample19.wav: 22,050 Hz 20,748 bytes 8 bits
- sample20.wav: 11,025 Hz 20,876 bytes 8 bits
- sample21.wav: 11,025 Hz 15,898 bytes 8 bits
- sample22.wav: 22,050 Hz 14,444 bytes 8 bits
- sample23.wav: 11,050 Hz 16,110 bytes 16 bits
That's 252,269 bytes for the sounds effects.
As you can see, each sample has different resolution and frequency, this is quite common with home-brew games. I'll convert all of them to a 8bits 8,000Hz, signed sample. Maybe I can use a higher frequency if I've some free space to improve the sound quality.
After conversion and packing the data I've 87,730 bytes, that's 34,7% of the original space or 65,3% space saved. If I need some extra space I'll use ADPCM encoding to reduce each sample to a 50% before compression.