Gyakuten Saiban series (known in English as Phoenix Wright: Ace Attorney)
TECHNICAL
Short ☆☆☆ (medium length)
Easy Japanese ☆☆☆ (relatively easy)
All / Almost all text is voiced ☆☆☆ (nothing is voiced)
Replay voice button ☆☆ (no voice acting)
GENRE
Mystery ☆☆☆ (awesome plot twists)
Comedy ☆☆☆ (awesome characters/comedy)
Action ☆☆ (mostly courtroom drama/murder mystery, so...)
LIGHT Romance ☆☆ (only hints of it, but still no stars I'd say)
GAMEPLAY / FEATURES
Gameplay / Choices ☆☆☆☆☆ (requires paying attention and finding clues, very rewarding experience)
"Transparent" routes ☆☆ (linear, no routes, so in that sense it's a plus that you can't get lost, I guess?)
True/good ending NOT based on pure luck. ☆☆ (You need to sovle the mystery yourself, so yeah, you have to work and consider all the clues/info to be successful)
PRESENTATION
Artstyle ☆☆☆ (good, but up to personal preference)
Voiceacting ☆☆☆ (no voice acting at all, other than a few sound effects)
Few extreme H-scenes ☆☆☆ (there are no h-scenes)
Total: 23
You could also look into non-VN games, your usual JRPG tends to use easier language, for example the Tales of series, or the two Shining games (Blade, Ark) on the PSP.