Well, there are actually good things to say. First and foremost, this is at least a really complex game. It's physics based, pushin boxes around, rotating some of the walls (which should be different from normal walls, btw, except if they are secret doors), timed lasers, two types of weapons that have limited ammo... All of these represent a good foundation in terms of gameplay variety. BUT, it needs a lot of tweaks first, if you want your playtesters to stick with it.
The worst part is that enemies shoot before you can see them. This might be good for "some" enemies, but not the first enemy you encounter. I "feel" like enemies should die quicker, at least the first ones, and different types of enemies may require more shots or even the bomb to get rid of efficiently.
I also recommend a higher resolultion line of sight mask sprite, or at least, you could make the edges end in a gradient. Lower the brush tool's (or the eraser's) hardness value to make the edges end in a gradient.
Currently the los grows and shrinks over time. But maybe you can make it so that it grows when you stand still, or maybe it shrinks when you are hit (and slowly grows back).
Give it a few new versions and I will keep playtesting.