a balanced game play is a heavy thing I know, it requires a long testing period, and a lot of testers (who can mod/tweak the game simply by e.g. editing text files), and a good source of collecting further ideas. it is difficult for an indie developer to collect a large tester team, but this feature has another advantage, in connection with what you mentioned: the taste of each player cannot be satisfied, but if a game is easily moddable, it can increase popularity, as a modding community can emerge and grow, thus your game can be developed more easily taking into account their work.

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grand theft horse crazy idea, I mean good! with some fight features like in mount&blade. and with buying selling stolen things. and finally make a group of raiders.