Steam Next Fest is going on right now and I thought "I should make a list of fun cyberpunk demos to try!" And then I looked at what cyberpunk demos were available. It's weird. I still decided to make a list of at least... interesting games I found.
Dystopika - A cyberpunk city builder. Like, you add giant buildings, cover them in advertisements and neon lights, and... I think that's it. Even the description says "No goals, no stress, no objectives."
DeResolution - There's no way this game makes it to release without a Cease & Desist. It's an attempt to create a Tron game and it's not even trying to hide that fact. The demo isn't listed on the game's steam page but it's available on the next fest page.
Mullet Mad Jack - A ridiculous FPS where you have to kill an enemy every 10 seconds or the game ends. I posted a link to a gameplay video a couple weeks ago. Now the demo is available.
Death Noodle Delivery - A paperboy knock-off set in a cyberpunk world where you deliver noodles on your hoverboard. I'm hopeful about this one, I like the idea.
packet.Breach() - A tower-defense game that uses hacking as the concept. I'm terrible at tower-defense games so it's hard for me to judge this one. I enjoyed the demo though.
Eden Genesis - A weird precision platformer where you just enter a room and have to collect all items and defeat all enemies within some period of time to earn a rank. Then you can walk around the overworld to find a new room where you do it again. It's wrapped up in a cyberpunk package, but it feels more like a series of puzzles than a cohesive game.
Veiled Edge - Another 2d platformer. This one reminded me a lot of Sanabi. Where Sanabi gives you a grappling hook for fun movement mechanics, this game has a teleportation mechanic. You move into "teleportation mode" where there are certain spots you can teleport to and you pick which one to use. Very similar to the "aiming mode" Sanabi had for its grappling hook. I should mention the demo defaulted to Korean language. I had to find the options menu and change it to English to make any sense of what was happening.
Memory Lost - A twin-stick shooter (like Ruiner), except in this one you can posses the body of enemies and use their weapons/abilities.
Also, since I'm listing games anyway, here are a couple demos for games that have already been released:
System Shock remake - A very faithful remake of the original System Shock. Meaning, it isn't as mind-blowing as the recent Dead Space remake. This remake keeps a lot of the rough edges from the original.
Turbo Overkill - A fast-moving boomer shooter with Overwhelmingly Positive reviews. You can slide on the ground and use your chainsaw leg to mow down enemies.
I don't do visual novels or RPGs but hopefully that's a diverse enough list for you to find something interesting.