I know the feeling.
I spent well over a hundred hours working on an adventure game from 2005-2009 or so, once only to scrap it at 80+% done because the engine I was building it with [Adventure Maker] was discontinued and would not support any future Windows OSs. That project - "Traveler's Enigma' died for good some time around 2010. I also launched a game for Android designed by my dad - he coded it, I did the graphics. It never made a single penny, after well over a hundred hours of labor from each of us. Ended up being rejected by Apple for iOS and made freeware for Android... and the CafePress shop connected to that never sold anything at all either. That was a giant misfire and it ended up quietly ignored by most everyone, on GalileeGames.com. I think the biggest screwup was the core concept - my dad, despite my skepticism of faith in general and thinking religion is stupid, he wanted to make a Christian themed game and apparently had no clue Apple would ban it for that reason. [Regardless of the reason they said they rejected it, which was jaw-droppingly vague, I suspect it was rejected due to its overt religious content. ]
There are two other indie games - "Isola" and "Vivid Minigolf" that likewise will be rebuilt/reworked code-wise entirely from scratch because the engine I'd used or tried to use initially was way too limited (GameSalad) so now I'm going to redo them in Unity and Construct 2 respectively.
Also made a little Myst fangame in 2004 with Adventure Maker and am now remaking it in Unity... along with a Unity remake of a project called 'Panoramic Worlds' which was initially built in a panoramic virtual-tour app plus some overlaid code.
So basically, off and on, I have built, to various stages of completion, close to a dozen abandoned / failed games in poorly-selected game engines. Thousands of hours poured into things that have never seen the light of day, and that's just the games. I have lost a bit of video content as well, in a few cases, and while most of it remains intact, it is STILL unlikely to ever end up online for the most part. Why? Legal issues. I have a scattered list of cast members wo've never signed talent release forms and in failing to do so ensured the video projects they acted in cannot be posted on the web without a risk of lawsuits.
It drives me crazy - I have been shooting comedies, action flicks, sci-fi shorts, etc, for two decades as a hobby and 90% of that is still NOT ONLINE. Maybe never will be. I put $5000-6000 into those, there's maybe 7 hours of video stuff there in all with 2000ish VFX shots combined. 10k hours worked doing the entire crew thing on my own - I wrote, directed, edited, did VFX and set design, makeup, props, etc, on several dozen self-financed video projects over 20 years... Generally that material is only accessible if I show it to you in person - it has mostly never gotten released on the internet. I am considering throwing a lot of it up despite the legal risk, maybe posting it in a giant zip file on a torrent site or similar. Would never make a cent, but at least then people can see it?
Thankfully, as far as gamedev goes, I now have a really decent setup with Construct 2 [for 2d] and Unity+Playmaker [3d] and most of the graphics and audio assets from a litany of failed projects remain intact so I can go through it all and rebuild in better software.
And I've learned to back everything up in the cloud. I use BackBlaze to do that and hopefully I won't lose my data any time soon even if a hard drive fails for no good reason as time passes, here and there.
My next project - the one game I'm mostly focused on launching right now - is 'Miniature Multiverse' and I am sure it'll be out there on Itch and Steam before this year is over. I've got a lot of work done on that and it's a concept that has some people very intrigued by it. I also have released a bunch of stock media / asset packs I've made with 3d models, textures, video elements. All of my projects that are released or near the point of being released, on Itch specifically, are here:
matthornb.itch.io. - a ton of stock asset pack material is on sale the next 48hrs, for a bundle price of 95 cents. Would be nice if this sale resulted in a few actual sales, reviews/ratings, comments, something, anything. :/
I've got a ton I want to do. I would like to do gamedev and art stuff and reworking of video stuff for online launch, full time but need support to get it all there.
I am not giving up but... I am wasting a good chunk of my time the last few years doing sub-minimum wage freelance and microtask stuff at around $3 an hour to keep everything afloat, while my own projects inch forward at a rate that's kinda glacial. Oh well...