Anyone remember "conflict simulation" table tops of the 70s and 80s, like Wooden Ships And Iron Men and similar ? They were 2D (well, cough, table top), often a hex based board with limited extent, entities with fixed or variable values, and a bunch of pretty simple formulas to calculate like relative strengths, effect of combat, resolution of hit or miss, etc. Together with a random element (dice) they made for a pretty nice waste of time. Not comparable to AD&D or Traveller style role playing ofc.
Easy to implement in an engine like Godot.
Only danger is probably not to violate any copyright thingies ...
