Enjoyable and addictive. Also hard, but not nightmare hard.
You've found a nice balance. If you plan on making a sequel,
then consider adding a story. It was sad to see that the robot
had his batteries depleted in the end, but this is not enough
of a story. Also, consider music, but I am not sure it will be
good, as this game had a very nice atmosphere. TLDR:
Gameplay - 5
Story - 3
SFX - 5
Enjoyability - 5
5/4.5