• Hi there! I just played your game on Android and I have some feedback / suggestions, and sadly not all positive.

Observations

• The controls of the game are not openly obvious as a user would expect W/O tutorials.
• Survivors and Zombies are a little hard to tell the difference between.
• The terrain seems very boring and lacks any form of variation.
• There are few / no main POIs that stand out in any way in the game and thus makes it kinda hard to direct the user's focus.
• Driving mechanics are dependant on the user understanding peddles as well as being right handed for the acceleration mechanic.
• The game world unnecessarily open-world and as a result the map seems to lose all sense of direction / meaning.
• UI does not communicate necessary information clearly aside from direction and time.

Suggestions

• The first thing I would suggest is allowing for a more helpful introduction to the controls with some form of tutorial.
• Secondly, it would help to rework the visual designs at least of either the zombies or survivors to help easier set them apart from each other.
• The terrain could use variation, maybe through using a fixed overhead bumpmap? Constant superflat also takes away from the challenge / fun of the game, along with the realism that you stated you were after.
• Having some specific buildings / environmental POIs that can help to throughout the game create a sense of direction and familiarity.
• I would suggest creating a more universally understood way of communicating the controls to the user, as well as options to allow for reconfiguration.
• It seems like you may benefit a lot from focusing more on potential map designs to give the structure of the game world purpose and help to visually direct the user in some ways too.

There ya go! I hope that this feedback helps you going further with this game It does honestly seem promising, and I am curious to see how it continues in its design and development