Paint 2 long walls same off white color. In DR an oval braided rug in green + gold tones. Buy same braided rug for LR but rectangular. Paint short LR wall in green (not too dark) that harmonizes with rugs, furniture & flooring. All trim white / off white. Remove: small table on right LR wall, tall dried arrangement on floor of LR and both art pictures in LR. Place one of the art pictures over the table with mirror between the 2 sliders. A brighter runner on DR table that picks up colors of rug. Add more green vine-type plants (Pothos). Natural wicker basket on top of china cupboard with Pothos. I wouldn't bother with curtains.

There's a few things that I think emphasize the length of the room: the table, the light fixture and the floors. They all direct the eye through the room. A rug under the dining table will help define that and break up the flooring. Oval (they are harder to find) or rectangular. Also a new light fixture over the dining table, that hangs at staggering heights or is round etc. would help. A round or other shaped table decoration would also play down the linearness. It looks like you do have a rug in the sitting area. If you had a larger one that went under the furniture I think it would look better but I can see multiple traffic patterns so that may not work for you. A larger rug with a print would be nice to define that a bit. You have lots of solids going on so don't be afraid to incorporate some prints. I would also paint the end wall the same color to close the space in. Wallpapering or painting it a different color just draws the eye down the length of the room. If you ever redo the floor in the future, I suggest a mix of sizes if you do tile. Photos aren't your style but to give you an idea of ways to trick the eye:


If you had the option of new furniture I'm sure there would be a different layout for you as well. Spaces like this are tough, good luck!

Building off CTDesign's idea to introduce more rounded elements - IF you can move the hutch/buffet, AND the width of the room is at least 12 feet - I think you could fit a round 60-inch dining table that seats six and still lets people navigate around it relatively comfortably.

It also looks like the far wall where the TV is located is painted a lighter, contrasting color to the side/long walls - which I think pulls your view down the length of the room and accentuates that bowling alley feel you speak of. I'd keep that far wall the same color as the side walls.

Just some thoughts - look forward to other comments.

Do you have room to rotate your dining table 90 degrees? That would break the long lines. I also think that your two ceiling lights pull the eye along as well.

Is there room for a low buffet or console behind what appears to be a loveseat in the middle of the room. If so, you could use it as a platform for a tall vase of flowers or grasses or a nice sculpture.

We faced this problem in our 30 foot combined family/garden room and solved it by making the far walls the focus of the room--dark paint and large wood shelves full of pots, etc. It seems strange, but focusing one to look at the wall makes it seem closer. I attach pictures snapped from the doorways to the room. Note that I did none of the things I suggested for you!

Have you tried moving the china cabinet to the back wall where the TV is and then moving the TV to that wall (further down) and then turning the couch to face the TV there? It may make the room appear bigger