For easy reading I’m starting with a summary and a longer version at the end.

Summary:

When developing my game some time ago (saying game X) I got contacted by a game publisher and signed a contract so (according the contract) they have full rights to publish my game X, however after a lot of time with lot of trouble I don't want them as a publisher anymore (with good reasons from my point of view).

Since my game is a very big (Misc game) open/global game about different things (A,B,C,D,E) very wide.

I decided to disregard the contract and change the name of my game (no name yet) and start game Y and only take one part of my previous game lets say A and change most of the GUI and a lot of other aspects of the game.

Now to get further in to detail and the actual question, how far do I need to go to get (rid of a previous) contract.

As I'm still using for example the same maps in the game Y as I did in the game X with the signed contract.

Would that be enough to get rid of a previous contract or are there more things going on? In general when is it a new game.

Longer info:

I have been busy with this game for a long time now as an independent game developer. And things are starting to really look amazing at the moment.

Some time ago a signed a contract with a publisher, and most of the things went good in the beginning.

However important things like advanced payments caused the main trouble as communication and deliveries of demo's were mostly always delivered on time from my side also according to the contract.

Other issues were the communication from their side as I never heard any response and mostly of bugs/QA/testing while in the meantime my over 100 beta testers giving me complete useful reports about all the issues.

After multiple further issues, and the publisher just keeps on promising things but not following them according to the contract I decided to cancel any further development of the current game and start working on a new game with new name taking only one part of the old game.
I have changed almost everything from the gui, functionality but of course some things remain from the old game mostly a few 3D objects but also some maps I spent a lot of time on.

The question is mostly, when is it a new game.

You want to terminate the existing contract, right? So look at what it says about termination in the contract. You'll probably need to hire a lawyer and have him write a letter, at the very least.

Or do you just want to make a new game that's based off the encumbered game, and get it published separately from that old deal? You'll probably need to hire a lawyer to advise you.

I want to avoid using Lawyers because of finance, so yes i'm trying to create a new game and mostly posting here if there are already people with advice on this issue.
At the end i probably still need real legal advice which is the next step.

Of course the contract says (in easy words) that if both parties don't fulfill their duties the contract can be broken, but as developer its ofcourse not always as easy as it sounds.

Depends on the terms of the contract. There was a publisher-developer dispute at where I worked where the publisher got a complete copy of all assets and source code, but my company also got to keep the source code and assets, but had to redo them for the game that eventually came out, I think it was mostly logo removals. I don't think the publisher did squat with the source code or assets, but hey, they got them.

Also, be careful that you don't have your name in the contract anywhere, or you could be personally liable (and not your company). It would probably be worth it to get a lawyer.

Thx Ferrous, that helps out also.
Terms are mostly simple except that they have the rights to reproduce the game although there is no game but only the title/name, there is further no mentioning on special things like sharing the source code/assets. The contract is based on my company name not my personal name.

Already had the feeling that this kind of issue is impossible without a lawyer / advisors.

I want to avoid using Lawyers because of finance, so yes i'm trying to create a new game and mostly posting here if there are already people with advice on this issue.
At the end i probably still need real legal advice which is the next step.

Of course the contract says (in easy words) that if both parties don't fulfill their duties the contract can be broken, but as developer its ofcourse not always as easy as it sounds.

Of COURSE you want to avoid the expense of a lawyer! But you also want to do something for which you NEED a lawyer. It sounds like your contract does not have a "terminate at will" clause, so you need a lawyer's advice as to how to terminate it. You could try just calling your contact at the publishing company and telling him you want to terminate it, but my guess is that after you do that you'll get a letter from the publisher's lawyer - and then you'll need a lawyer of your own.

Yes i think the lawyer is the only choice up here (also to be really sure). Also your latest line will result in your answer i'm afraid also.

The purpose of the post was also a bit about how much i needed to change but ofcourse there's a lot of things still going on even with that.
I think its best for now that i just forget about anything everything used in the previous game. And ofcourse get in contact with a lawyer specialized in this kind of thing.

I'm not that familiar with game publishing contracts although i did a lot of research and i think the 'terminate at will' seems very rare, the terminating reason clauses only involves things like when one of the parties don't fulfill the agreements in the contract (what actually happened) but of course it has to go to court to use this clause.

@braindigitalis no i didn't take legal advice when i got the contract and that would be a good advice for all the people up here getting their first contract.