Thanks! Yes I absolutely agree on those things. I reduced the player's shot range because originally the only way to aggro an enemy was to shoot them (hadn't added the bats at that point) and it made things too easy. Definitely need to look at that.
Yeah re: the theme it's is mostly via the background, didn't manage any overt references via the gameplay - the day I lost on the WebGL issues I had down to add some dialogue, alas time ran out. Cheers for the feedback, really appreciated.