I'm trying to familiarize myself with UDK because I am going to make a game with a similar feel to Which by Mike Inel:
Making a game like this without an engine is too tough a proposition, at least if I want it done in a reasonable time.
UDK includes an application for creating particle systems, which is fast and painless compared to defining them programmatically. It also has a versatile node-based material editor. To get started I put together this particle system of spinning circles, which follows the player around the default scene:
The vision for the game is currently a mix of ideas from Silent Hill 4: The Room, Which, and the dream sequences in Max Payne.
The game should only have about fifteen minutes of playtime in it, but could take a while to make, depending on what design decisions are made down the line... I'll post more as I get some milestones ticked off. Hopefully it'll be done before the year is out!
26/01/2013 - Ah well, I didn't pull this one off. It was too ambitious. One day, maybe.