update 0.1.2

A new update to the game. this time aiming to make it more enjoyable, and maybe just a little less brutally hard.

+ added shield batteries: Killed enemies now drop batteries that can restore your shield. This should make the game more winnable, and also incentivise fighting enemies over running past them all the time.

+ added indicators to weapon pickups: Fairly self-explanatory, should just make them more obvious and distinguish them from level props.

~ widened up multiple vertical shafts where you had to fight enemies: Lining up shots in these could be annoying, and they made it hard to dodge. There are still a few, but they are outside of areas where you will be fighting.