Trine

It seems that the style of the cheap, downloadable puzzle/platformer is becoming more and more popular, and usually these games do a lot to reinforce the ideas that innovative gameplay and general polish make great games.  Trine seems to be in that vein, because it does offer interesting new gameplay mechanics, but suffers from a lack of really sound design on a few fronts, and its problems tend to drag down what could have been a really excellent title.
 
The basics for Trine are very well imagined - you switch on the fly between 3 characters with very unique abilities to progress through 2D levels that involve combat and physics based puzzles.  The physics almost always work perfectly, and some of the puzzles are fun and challenging, but the majority of them are pretty standard and simple.  The Wizard character is the most useful in these situations, because he can conjure objects as well as levitate things around the level, so you really have a lot of control over the environment.  The Thief is what I mostly used to move around the environment, because she is equipped with a grappling hook.  Sometimes the physics on the grappling hook could get a bit weird, and I found myself sort of cheesing the system by grappling to things out of view that I didn't feel like I was supposed to be able to grapple to.  The Knight doesn't really serve much purpose for puzzle solving or platforming - which I suppose means he is intended for combat.
 
Unfortunately, the combat in this game is rarely fun or challenging - and when it is challenging it is mostly just annoying and most definitely not fun.  Throughout the game you'll fight a whole lot of skeletons and bats.  Skeletons are really dumb, and don't really pose any threat to you, other than the threat of them toppling over your carefully stacked tower of crates that you just spent 5 minutes constructing.  The worst part, however, is not when they knock over your tower once, but when they knock it over, you kill them all, you wait to see if there will be more, rebuild your tower, and then one more shows up to knock it down again.  This is a constant problem through the game - where enemies sporadically appear one at a time just to mess up your platforming and puzzle solving.  The bats, on the other hand, won't mess up much, but will slowly drain your health away while you try feebly to hit them.  They are what I meant when I said challenging but not fun, because your characters just don't have anything to deal with over-caffeinated bats.
 
Overall the idea behind Trine is a good one, but uninteresting puzzles and environments coupled with unsatisfying and generally downright annoying enemies really take this game from high potential to sad execution.