So, do you want actual game ideas, or do you want ideas about how to come up with ideas? The former I can't help you with; good ideas are rare enough that I wouldn't easily let go of one
But if you want some advice on brainstorming: Get a few sheets of paper and write down all of the thoughts occuring to you. Even (or especially) those that seem silly to you, it doesn't matter. You're not going to keep those sheets, it's really just a helper to get your thoughts going. Any thought (even the silly ones) will trigger more and more thoughts, and eventually you're going to end up with a few that are more useful
It helps to focus your brain, though. Write the topic of your brainstorming into the centre of the sheet, then collect your thoughts around those in a mind map or cluster style. Given what you want, you could try to write "addictive" into the middle, or possibly a suitable genre, like "puzzle game". Then, write down all the thoughts that come to mind when you think of "addictive" or "puzzle" and write them around on the paper.
Another technique that can be great if your thoughts appear to be blocked: Write your word on a new sheet of paper, and then for each letter of that word write down a related thought which begins with that letter. For example, for "addictive" you could come up with "amazing", "tetris", "easy gameplay" for three of the letters. You get the idea
This is not immediately helpful to get an actual idea for an addictive game, but as I said, the primary objective is to get your thought process going.
What also helps is to team up with others and set yourself time limits. For example, jjp and I just completed one of those "game in a day" projects (although we decided to use two days, or 48h, but still). This means that everything, from idea to planning to implementation, happens within 48h. This ensures that you can't overthink everything since eventually you have to get started if you want to finish in time. I think we derived our game idea after about an hour of collective brainstorming and used the rest of the time for implementation. Now, what you can do in 48h is limited, of course, but it gives you a chance to just try something out, and even if it doesn't work or doesn't impress, you haven't really lost anything and might even gain new ideas as a consequence.
In our case the end result is a pretty decent puzzle game, although the gameplay does have its weaknesses. If you'd like to see it,
go here.
Anyway, I hope this post was at least remotely helpful. Don't pressure yourself too much, and good luck
