Upgrade design is great you feel powerful by the increment and not too fast not too slow. Sound is fantastic it is extremely satisfying to hit things and you can feel much that you are more like a tank by the end from the amount of hits. Difficulty system made it easy to grind if needed for the next level but the extra amount of scrap always made me push further. I did notice I could not access any of the options outside the main menu after starting the game. Wish it had a global button to press :(