To me there is a huge difference between games that offer a few levels for free then charge for additional levels, versus those FTP games that sell "bags of gems" to speed up timers or have pay to win game mechanics.
Very much this. Games that are "free to download and play the first level(s), then pay for additional levels or expansions" I have no problem with whatsoever - it's much like the shareware games (Doom and such) of old. (I also have no problems with "you can buy a different colored hat for your player", that is more like a donation because you enjoy the game, while not affecting actual gameplay.) This is an understandable response by developers to the situation that users have been conditioned that games "shouldn't cost anything" up-front.
It's the games that are "pay for consumable things and/or to bypass arbitrary timers that are here... to collect cash from the user" that I (and I'm guessing many others) have considerable disdain towards. (Skinner box cash extraction device.)
Feel free to keep reviewing games of the "pay to unlock more levels/expansions" (or hats) type.
As far as the game being reviewed here goes, I kept thinking, while reading the review, "this sounds like it borrows an awful lot from that game that I like but haven't played in a while"... yeah, I went and looked - the game I was remembering was, indeed, Auralux. Duh. Had fun with it, this sequel ought to be entertaining.