Nice idea, I liked it! It did seem I walked straight into beam as I moved up a screen a couple of times but that could be changed easily. Would be interesting to see the enemies move about a bit and maybe some kind of "View Cone" based on light something light this: https://assetstore.unity.com/packages/tools/particles-effects/2ddl-pro-2d-dynami... that could really ramp up the stealth element!
Thanks for doing a HTML version so I could play!