Unfortunately, I feel like this game needs a lot of improvement. Here are a few suggestions.
Only being able to move backwards and forwards really takes away from the movement. I think it would control a lot better if the player could use the W A S D keys to move up, down, left and right.
Ctrl is the key for deploying the shield. The problem with this is that when I press Ctrl to deploy my shield, then press W to move forward, it triggers a shortcut on my computer that exits the game.
The combat would be a lot better if the enemies moved around and maybe even chased you.
While playing the game I noticed that I could kill the enemies in the first hallway without them fighting back, because I could just stand outside of their attack range and shoot them.
I hope my feedback helped. Thanks for submitting this game.