OK in the end I bought Blue Toad Murder Files because Epsiode 3 is free until 25th March...
Its quite fun, the over-eccentric narrator definitely keeps a bit of the interest there.
At the end of each episode you have to identify which of the suspects you think committed the crime (I got it wrong all three times lol!)...
Through the game you question the locals who only give you information if you help them solve their dilemmas, in the form of puzzles... this is the interactive parts you partake in, but you do have to pay attention to the narrative parts too for the final "Whodunnit?!" part of the chapter, and also spot checks in the middle of the episodes.
for £9.99 I got a fair bit of gameplay, but the only replay value is going to be going through the puzzles again to get gold ribbons on all of them (you're awarded gold for completing puzzles in under a certain time and making no mistakes)...
The other 3 episodes will be released in one pack at £9.99 again so you'll be looking at around 8 hours gameplay for £20, which is a shame as the game is enjoyable but, once its done, its done....