The "sliding along walls" feature was one that I had planned to put into the game, but didn't do before the end of the jam. I had been testing using a gamepad, which I think makes the game much more enjoyable than playing on keyboard. However, I respect that the overwhelming majority of players will be using the keyboard as their controller.
I decided to upload version 1.1, which implemented the sliding as well as a bug fix; Sherlock Jack's sprite should blink when he's reeling from a hit, which had been working in an earlier version of the game, but as the rendering got improved, that feature got disconnected.
I encourage other people checking out the game to decide whether to play the 1.0 or the 1.1 version (I think that itch.io will make the 1.1 version easiest to play, but if you're a Game Jam Purist, 1.0 should be playable, just more work).
As far as dead ends go, that's just how the streets of London are laid out - if that makes this game too annoying, I'm sorry. I had been considering providing PDFs for something like 48 procedurally generated (and then fixed) neighborhood maps, so that players could print them out and use them for navigation to their next destination. I ended up going with doing the generation on the fly, which feels fine for an action game.
I could (well down the road) do a pass on the city map and prune out some of the dead ends. I'd probably have to generate a lot more street segments before pruning to get to approximately the current city size.