Yeah we did intend on having the bullets not go through the tiles, we just didn't get the time at the end to set that up and still make the submission deadline in time.
In regards to the pulse signal direction, the wire changes to the colour of the character that can pulse at that given time. Although I do know it is subtle and not very colour blind friendly. We did have a HUD element indicating it towards the end, but lost it in a scramble to squash a bug in the final moments.
Thanks for the feedback, greatly appreciated!
-Scott