- Definitely a setting that appeals to my sensibilities.
- Could have done more to sell the thematic flavor, especially for the Communist aspects.
- Would have benefited from sample locations and/or enemies
- Suggested weapons or vehicles would have been helpful to sell the motif.
- Another possibility: specific mechanics for using vehicles and equipment, especially for combat situations.
Doesn't need to be overly complex. Just enough to distinguish your personal vision from the basic Tunnel Goons rules.