The Switch 2 is backwards compatible with most games from the original Switch, but in these early days that compatibility isn’t quite perfect yet. However, even games without explicit Switch 2 patches can benefit from Switch 2 hardware.
Unfortunately, some games are being held back from playing at their best not by the developers, but by something that Nintendo itself can implement—forced docked mode in handheld play.
Switch 2 BC Seems to Work Great for the Most Part
The way that Nintendo has handled backward compatibility on the Switch 2 is a little different from how its done it on previous consoles. In the case of the Switch 2, there’s no direct hardware compatibility, but instead a hybrid approach using some hardware compatibility, some translation layer magic, and maybe a dash of emulation here and there.

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This is why Nintendo maintains a Switch 2 backward compatibility list which details the percentage of games on the Switch that will run, which run with issues, and which ones don’t run at all. Nintendo isn’t testing these games thoroughly, mind you. So it’s entirely possible that players will discover problems with games in the “no issues found” section of the list.
In general, however, I expect games that run correctly for the slice that was tested to run correctly overall. In the various videos I’ve watched where this feature was tested on the Switch 2, it seems that even games with no special patches will, at the very least, no longer experience frame drops, even the notorious Batman: Arkham Knight, as you can see in this Digital Foundry video:
Games with unlocked frame rates on Switch, will max out on Switch 2. Games with dynamic resolution scaling, will simply sit at the top of the set resolution range.
Oddly, Switch Games Still Seem to Run in Handheld Mode When Undocked
However, there’s some bad news here at the moment. The reasons for that is that these games have resolution and performance limits set for the original Switch in handheld mode. So, the highest resolution a game will achieve is 720p, although it might target 1080p in docked mode on an original Switch.
So, despite having a 1080p screen, these games will only go to 720p (or less!) and undergo an ugly upscaling process to reach the native resolution of the Switch 2 screen.

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While I don’t know if this is true for every single game, every game that I’ve seen testes to far seems to be limited to whatever the original Switch handheld mode settings were when in handheld mode itself.
Forcing Switch Games Into Docked Mode On Switch 2 Seems Logical
It seems to me, that the most logical thing to do here is force Switch games to run in docked mode on the Switch 2 all the time, whether docked or not. For most games, this means we’d get the full native 1080p output the docked mode that game aims for, which would lead to a significant improvement to image quality.
For all I know, this is something Nintendo intends to do going ahead, but I do wonder why Switch 1 games aren’t running at their best settings all the time on Switch 2. Perhaps there’s some aspect of the docked mode that won’t play well in handheld mode, such as power management or maybe the dock would have to be emulated for some reason.
What is true is that some games, like Mario Maker, wouldn’t work correctly in handheld mode if they were forced to run using their docked mode settings, because they need the touch screen, and that input is disabled when docked.

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Nintendo Should at Least Give Us the Option
Whatever the technical issues might be, it would be nice if Nintendo simply gave us the option to toggle a forced docked mode on for each game, and decide for ourselves whether the results are worth whatever compromises there may be. Failing that, our only hope is that the developers of these games will patch them to allow for higher resolution and frame rate caps. We’ve seen this happen on, for example, the PlayStation 5 running certain PS4 games.

- 4K Capability
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Yes
- Brand
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Nintendo
The Nintendo Switch 2 is the company’s latest hybrid home console, with more powerful graphics and processing, a larger 7.9” LCD touch screen with support for HDR, and more online features.
In principle, adding this option to Switch 1 games shouldn’t be that hard for devs that are willing to do it, since it effectively boils down to simply increasing a range for a function that’s already implemented.
As it stands, you can play nearly all of your Switch games on a Switch 2 without issue, but in some cases games can look worse than they did on the Switch because of poor scaling. Here’s hoping Nintendo makes this small tweak sooner rather than later.