As an example, find and load "Supreme Commander" and its sequel "Supreme Commander 2". The original was, IMO, the best RTS game ever developed. The sequel was digital vomit - worthless resolutions, nonexistant gameplay flexibility...just a complete FAIL.
SupCom2 is not as bad as you make it out to be. The situation and goal for SupCom2 was simply completely different. Total Annihilation and Supreme Commander were excellent hardcore strategy games (and imho the only "real" real time strategy games worth playing. Every other RTS game is simply a more advanced, artificial tactics game). The problem is however, that the target audience for such games is very small and the scale and scope of these games made it very demanding on hardware, which reduced the potential player base even further.
If it weren't for THQ, SupCom would never have happened, most publishers didn't want to take a risk with such a niche game. Supreme Commander was a success in terms of revenue, but of course no money making machine. It made enough money to warrant an expansion and some support after each game. If it were up to GPG, they would have loved to give the game much, much more support, but money was simply lacking (and developers do not run on fairy dust, they need money for living
).
In an unexpected turn of events, Square Enix decided to fund a sequel, however, they only offered a limited budget (about 3 million compared to the original 10 million dollars of SupCom1) and the condition was to make the game more accessible and also develop a XBox version in house. Otherwise the game simply wouldn't have been profitable. GPG did a good job here, considering the conditions. The game became more Crafty, but still aimed more towards the features and scale of the original games.
