It's free on Steam, so it would have to really suck to not recommend it.
This is a very simple game with no instructions at all. All you do is move left, right, shoot, and select weapons.
There are 10 levels. No real story. Old school graphics.
If you want something to give you 5-20 minutes of gameplay, you could do worse...and better.
Bloody Walls
Bloody Walls
“Activism is a way for useless people to feel important, even if the consequences of their activism are counterproductive for those they claim to be helping and damaging to the fabric of society as a whole.” - Dr Thomas Sowell