It's late at night, and I'm kinda sleepy, so these responses are probably not articulated well.
1) Which version did you play? Windows, Linux, or Mac? And did you run into any bugs or glitches?
I played the latest version of the demo on the Mac. No bugs or glitches.
2) What was your overall impression of the demo? Did you enjoy it? Did it keep your interest?
I enjoyed it, and I'm definitely interested, but I'm a bit disappointed with the length. It was still pretty fun, though. I'm looking forward to the extended demo!
What did you think of the animated backgrounds (i.e. the heat wave
effect)? Did it add anything to the experience? Currently, there is an
option in "settings" to turn the heat wave backgrounds on and off.
I thought the heat wave effect was cool, and the option to turn it off was much appreciated because I got a bit dizzy after a while. It gave off that summery feel, and it really added to the atmosphere.
4) How was my overall writing? Did it flow well? Was there any moment that you felt the dialogue was awkward or stilted?
The writing was pretty solid, but I think you could've worked a bit more on how Rin gets involved with Leon and Ryan. I also love the dynamics between Nico and Rin; he's my favorite love interest so far. Gotta love those mischievous types.
Was there anything that you didn't like about the game or that you want
to be changed? Do you have any suggestions for improvement? This
question is especially important because I'm still at the stage where
tweaking and changing things around is relatively easy.
I know you're tweaking the GUI design, so you'll probably already have taken these into consideration, but I kinda wish there was an option for adjusting the transparency of the speech box. I really appreciate the style of the game, so I really wanted to see more bits of the art, as in the characters' clothing and a bit more of the background. I also found the text used a bit jarring. It wouldn't be bad when used for titles/headings, though. Also, you could only name your character once, which was kind of humorous, because I named Rin "George Washington" and I didn't know it was unchangeable until I did a second playthrough. Oops. My suggestion is that you can be allowed to name Rin at the start of a new game/playthrough. The name thing isn't really important, though.
6) What was your favorite aspect/part of the demo?
The style, design, art, and theme for the main menu was pretty great. I thought it was cool when Rin opened her eyes if you began a game. The funky, kind of punk-ish/hip-hop aesthetic of the game was also rather neat. As for favorite parts story-wise, I really liked it when Rin said her rather sassy dialogue. Speaking about Rin, I love her, even more so than Nico, haha! I also think I'm smelling a tragic backstory on her. I'm interested in finding the reason behind her adrenaline junkie trait, and why she was probably dead in the beginning of the game.
I might edit this tomorrow for grammatical reasons/writing in better answers. Anyway, the demo was pretty good, and keep up the good work!