Seems like it's more of the habits you have, that are leading you to feeling 'unmotivated to work on side projects'. In your free time, you're in the habit of doing something that gives you instant gratification and pleasure, that is video games, instead of doing something that seems like work and will provide pleasures (of learning, getting results etc) much later.

What I would do is to employ a technique called 'habit stacking'. Meaning:

- Take the habit you already have - that is playing video games in your spare time.

- Make a small commitment to yourself, that whenever you will feel the urge to play a video a game, instead of following the usual routine: turning on the console --> choosing a game --> playing it, you will add 5 minutes working-on-my-side-project habit right before. So your routine becomes: feeling the urge to play video games - working on the side project for 5minutes - turning on the console --> choosing a game --> playing it

That's it. You're taking the habit you have, and inserting a new, desired habit right before it.

Some extra tips:

- 5 minutes working on your side project could be spent researching, ideation, sketching, coding etc.

- I know 5 minutes looks ridiculous and it would take ages to produce any tangible result, but at this stage, don't focus on the result, focus on becoming a person that works on his side project regularly. 5 minutes every day is regularly. You might feel the urge to keep on working for more than 5 minutes, but make a conscious effort to stop after 5 minutes - this way you will develop a craving.

- print out the calendar of the next 2 months, stick it on your fridge and mark X on the days you actually worked on your side project at least 5 mins. Try building a chain. If you miss a day - don't stress, come back to it the next one.

- of course, 5 minutes is just an example - you can do 10, 15 or 3 or whatever. It just has to be an amount of time that looks ridiculously small and you'll be able to do it, even if you're unmotivated.

- Do this for 1-2 weeks and then increase your base time from 5minutes, to let's say 10. Repeat that for another 2-3 weeks and you'll see how you'll end up having a habit of working on your side project before playing video games. It's nothing wrong about wanting to unwind after a day at work. We're not robots. But if you want to have positive changes in your behavior - don't approach it with all-in-or-nothing attitude - this fails 99% of the time.

Good luck!