I really enjoyed Dave the Diver on my deck, I’m only 9h in but didn’t play for a while due to lack of time.

Another one that isn’t really my thing but uses practically no battery is Minecraft through PrismLauncher (I don’t like playing Minecraft on controller).

And some other games from my library that play nicely on deck, some might take a little bit more power:

• Celeste
• Geometry Dash (especially with the new platformer levels)
• Hue (might be a bit boring, I got it for free)
• Pole (might be a bit frustrating, I got it for free)
• Rayman Legends (there’s a certain patch to make it run without uplay)
• Stardew Valley
• Turnip Boy Commits Tax Evasion
• Turnip Boy Robs a Bank
• Undertale