"This isn't an issue, it's a recycled sprite and is intended because pixel art is really expensive.
I've left it in for so long because it seemed fun and used the art budget at the time on other animations."
Ok. I assumed you made the pixel art yourself.
"The doors is intended as a workaround to a collision bug in Unity/PhysX where if you have two separate colliders next to each other, even if they're exactly lined up perfectly, other colliders (i.e. the player) will get snagged where they meet, causing them to stop moving."
I see. I have not used the Unity engine before.
"Controls are included in the README.txt located in the .zip bundled with the game, these controls include the keys for diagonal aiming.
They're shown here in the Controls Menu, although I apologize for not expressly naming them "Aim Diagonally Up" and "Aim Diagonally Down". I will include this change in the next update. Should probably remove Inject Tank as well since that's a disabled feature."
Strange. I was aiming the joystick diagonally. I also tried my left and right triggers but nothing happened.
"If you look at the map tiles, you'll see they follow the controls, they're not actually inverted. Might look that way because of the grid."
It was still confusing though. I recommend you change it.