I went for 2/10 and 6-10 hours.
I really enjoyed the game. It's a great intro to the PS5, and a fun, well-crafted game in its own right that is great for long-term fans of PlayStation.
The game doesn't offer up anything too difficult. There are a small handful of artefacts and puzzle pieces that are tricky to find. I got most of them on my own following one or two runs through each level. There were a couple of collectibles I referenced a guide for, and I needed to do the same for the miscellaneous level-specific trophies. While only required for the add-on portion of the game, the final boss was probably the trickiest part, but it only took a few tries. The speedruns (also only part of the add-on) were very lenient in terms of the overall time limits.
It took me about 9 hours from first to final trophy, but this included some breaks. I'd say it was closer to about 7 hours of playtime in total. I did have to play some of the levels more than once to get some collectibles I missed out on first-time, so you could do it faster if you work with a guide from the start, although it's probably more fun to play without a guide for your first playthrough, and it only takes an hour or two at most to backtrack.