You have to be around my age to have even played this and even then you have to go back in time in your head to even imagine that any of these games would be even remotely fun.
If you could go back to the early 80's with a PS4 and show the people at Atari what modern gaming is all about they would probably worship you as a god... or kill you and steal your PS4... one of the two. Atari wasn't the first home console, but they were the first successful home console and can be considered the benchmark for what to do, and later what NOT to do, as a video game company.
These are what I consider to be their best games and do keep in mind that the CPU was a 1.9 mHz and 128 bytes of RAM and early games had a max capacity of 4 kB.
Joust
So you are a knight on a flying ostrich who is being pursued by other creatures that are also on flying ostriches in a conquest to capture a certain number of giant eggs in order to advance to higher levels. There are also dragons and lava... what's not to love about that?
Spy Hunter
Spy Hunter was one of the most popular arcade games of the age and just like any arcade game ported to home consoles at the time the arcade was leaps and bounds better than the home version. There were two segments to the game; one on the road and one on water. You would use a variety of weapons to evade pursing vehicles and dodge obstacles in the road/water to get to the finish. This isn't terribly innovative in itself but it somehow just worked.
The really cool thing about this game is that (as far as I know) it was the only game on the 2600 to include a special adaptor to allow the use of 2 controllers for a 1-player game in order to fire both forwards and backwards at the same time. This could have had so many more applications in other games but it wasn't used. Pity!
Warlords
There were a lot of brick-breaking games on the 2600 but very few of them made use of the "paddle" controller that came with every system. This game could be played by up to 4 players simultaneously and it pit you against your pals who would all be eliminated eventually.
I can't say for certain exactly what you are protecting here - it looks like a turd or i dunno what, but it must have been important. This really should have been followed up on because the replay value was immense.
Frogger
One of the most iconic games of the decade, Frogger's objective was simple: get to the other side without getting hit by a car or falling in the water. Falling in the water didn't make a lot of sense because you are a frog but I suppose it's about as realistic as flying ostrich knights. The game would get progressively more difficult and as far as I know it didn't have an ending - just like most Atari games.
So there are 4 of what I plan to have as a top-20 for the system. There were a TON of games on the 2600.
One bit of lore about the Atari that is kind of interesting is that even though it looks terrible, as you would expect from a 40 year old system, it originally retailed for $199 which if you adjust for inflation was over $800 in today's money. They sold somewhere between 25 and 40 million units. That's a lot of money!