Plugged the first load of sound effects into the game today, and for the most part they work quite well. 
In the weekend I went around to a friends house and we used a microphone and an audio effects processor to create a bunch of sound effects.
It was my first time creating sfx from scratch – And well, we didn’t have much of a clue really. We just banged stuff together and pitch shifted a bunch of vocals. My favorite noises were the Orc sounds, which aren’t in the game yet but when we were recording them the dog took exception and started growling at our down-pitched grunts.
Getting the SFX to sound decent whilst not blowing up the filesize has been a bit of a problem. To tackle this I’ve made all the SFX mono and most are 22khz 16 bit, with the occasional 11Khz sample. The sound effects that have the least ‘going on’ are more suited to downsampling – I’d suggest avoiding 8bit samples as much as possible, as they can introduce a nasty hiss, which really affects the sound quality.
So far I’ve added about 200kb to the download size with the small number of SFX I’ve added. Bringing the total filesize of the game to 700kb – I’d still like people on dialup to be able to play, but surely they’re used to waiting for everything by now 
I’m going to try to make the game less than two megabytes, but it’s gonna just get harder the more stuff I add.