Hi Everyone,
I've tested all of this week's free games from Epic & Prime Gaming (Epic & Gog).
All games below were tested on a Steam Deck OLED 1tb using the default settings of the game upon install/launch (unless stated otherwise).
Our Steam Deck is also set up as follows:
Junk Store: v1.1.8 (Decky Store Channel is Main)
Decky Loader: v3.0.4
Proton Version: GE-Proton9-20
Steam OS: 3.6.20 (system update channel is Stable)
Other Plugins we have installed:
Wine Cellar: v0.1.6-cf38b52
Prime Gaming Giveaways (Epic & Gog)

GRIP: Works out of the box, no issues. It has native controller support.
SteamWorld Quest: Works out of the box, no issues. It has native controller support.

Are You Smarter than a Fifth Grader?: You need to install C++ runtime and run the exe to install it. You can then launch the game, it has native controller support.
Epic

Escape Academy: It has been previously given away and tested. It works with native controller support. I can't remember if you need to verify it with your Epic account or not but if the window doesn't open in game mode then launch it in desktop/Big Picture Mode to verify.
If you try a game out through Junk Store that works, and it's not yet been added to our wiki or tested by us, please let us know. If it requires any special work around or a different Proton version please let us know that too.
If you want to see a more comprehensive list of games we have tested in Junk Store check out our wiki:
Have Fun Gaming Everyone,
The Junk Store Team