OK. This is only my first day of playing this, but I think it's just enough for me to do a review/verdict.
Generally I thought this was an excellent idea combining Lemmings with Tetris. Putting that into perspective really does make it a great looking puzzler. The Graphics are great, tutorials are easy to follow, and the controls are easy, especially for the PC.
Basically you have "Three blind mice" and you guide them from the hamster wheel (The Entrance) all the way to the cheese. The tetris blocks shown at the top of the screen are there to guide (or hurt if you aren't careful) the mice through the level. There are 7 different rotatable blocks altogether, with each shape varying depending on the level. The default block is unmovable and act as terrain. Some blocks come with an effect, depending on the look. Jelly blocks can save mice from large falls, TNT blocks detonate when a mice comes in contact with them, electric blocks will kill the mice and movable blocks can be moved by the player. The blocks can also be used to pick up shards (Which are helpful for getting a perfect result) and bombs (Which destroys a block of the player's choice). There are also some ratoids which behave like the weasels in Lemmings Revolution, eating any mouse it comes across. There's also some water and acid in some levels. Mice can survive for 10 seconds under water, but sometimes that can be useful to survive drops, as it slows the mice down; while acid instantly kills the mice, and dissolves any part of a block as well.
There's a wide range of in-game options whilst playing. Unlike lemmings you can release the mice anytime you like. There are fast-forward, pause, restart and undo buttons. There are three different grades you can get for solving each level; Passable, Good and Perfect. Good is for getting all three mice home, and Perfect is for collecting all shards as well.
Now about the editor. Very easy and fun to experiment with, and you can be as ambitious or as simplistic as you want. The editor basically displays a grid at the centre of the screen. It comes with an objects menu on the left side, such as terrain, wheel, cheese, ratoids etc. The blocks at the top of the screen, and a file menu on the right side. The file menu also has a handy test level option. You can choose one of four styles (which also affect the look of the terrain) and how long you want your level to be (Unfortunately, not how high, although that's the only downfall I can think of).
To sum it up, despite the complete absence of multi-player I highly recommend this puzzler!