all the things i noticed

1, the enemies all immediately beelined to me as soon as i started, litleraly. a massive column of enemies poured out from one of the rooms toward me, only stopped by the magic barrier between the chairs and plants. 

my advice,  Unity has a thing called a raycast, if you have your enemies use one while looking at the player, you can test that ray to see if it hit  the player. then, if it did, you know your enemy has direct line of sight with the player and can go bananas attacking. 

2, the enemies are very strong, especially as a massive grey blob. reducing their health or their numbers would be nice, a few tanks or a lot of weak ones is nice, but a lot of tanks less so. 

My appologies if this is overly negative, these are the things i see and how i think it may be helped. everything else is great, and i think you have great potential, i look forward to your next game! :)