Cheers for the feedback, fellas!
Unfortunately I haven't got any experience in making any music, by the time the game was almost due I also didn't have any time to add any.
As for the balancing issues I'm quite aware a lot of people have had problems with the difficulty, although the player can gain advantage over the enemies by sneaking behind them and ducking under bullets (Whilst not on a ladder) I feel like I should've made it come across as a bit more obvious.