So far so good. Some initial comments would be that the tanks are really hard to deal with because they are the same color as the ground. A better solution than changing the color might be to add a secondary weapon so you can shoot downward or drop bombs.
A good start. My biggest problem at the moment is that I can not see my health from where I am looking at the screen to play the game. It should be closer to the action so I know when I am dying, or I need to start blinking or something. Beyond that I would really like to see more customization for the characters themselves: weapons, armor, etc. These are all things that could be equipped and or sold between levels.
i should be able to hover over or click on the features I have already bought to see what they do. For example I missed the text for the stamina plus feature, so I have no idea what is driving it.
There are too many jumps that the character can just not make that are required and how does the giant truck run over explosive barrels and monsters but gets stopped by a piece of wood on the ground?
one of the weapons unlocked allows you to fire downwards... :D