Nice game! I didn't really need to place lights and I preferred to save them in order to increase my health, so maybe instead of just emitting light they could do something else like keep enemies at bay, etc. I appreciated the 'attack with the mouse' mechanic but didn't see a reason to switch between weapons - unless I missed something? Such as unique enemies that require specific weapons to eliminate etc...
Congrats on your first game! It's a solid entry and well executed!