Cool idea, but I found the best strategy just to mash buttons to combine towers as quickly as possible. Also I think one of the interesting things about this could have been trying to balance the need to combine towers versus needing to position the towers carefully, but I think as it was it didn't matter too much where the towers were positioned as long as they were near the front. Having said all that, I did enjoy playing :)

This game is a cool idea and very original mixing the two genres!

Neat idea! I enjoyed the look and feel. The puzzle-y nature of the tower placement seemed to contend with the onslaught of enemies. If you'd like to focus more on the puzzle, perhaps playing with the camera placement could help communicate this. Otherwise, if you'd like to focus more on the action, you could expand the puzzles to be more forgiving or complex in setup (instead of just being 2048).

Really fun, needs a restart button though. Since losing still takes such a long time once you screw up (the fun of Three is that when you mess up you restart immediately) it kind of ruins the experience. I would recommend scoring by zombie killed instead of time survived (or maybe both) so the users sees how well he is doing. 

As others have basically said, the enemies start off too strong. If they started off easier it would give the player more time for their initial strategy, then as they got more difficult it would become more frantic as the player tried to keep up with the challenge. However, it is easy to get stuck with a full board and not be able to continue, so some method of clearing part of the board (maybe at the cost of your best tower as a trade-off) would keep the game going.

Otherwise, I really like the game. It's an interesting blend and the presentation is pretty good. I find it's more of a 2048/3s game with something extra, rather than a tower defense missing a mechanic though.

Very nice! I like the puzzle idea, but I feel that you don't get time to solve the puzzle while being rushed by the zombies, which ends with you just shifting the towers at random and praying for a good result.

Really cool idea and execution. I love how you have to move the towers to combine them into better ones and I though I was being baller when I was getting level 4s and 5s before the wave started! Then disappointing when it I was unable to stop a single unit though I had high powered (or so I thought) turrets. Perhaps starting the waves a bit easier it be nice. Eventually I filled all slots so I was stuck with why I had and at times it felt like I was losing some of the 4, 5, and 6s level turret. Still, I had fun just figuring out how to power them up. :D 

really good concept that definitely could be made in to very good full game. By now it is very basic but there is loads of potential to create power ups, new levels and different towers.

Really fun concept with lots of potential! I like the familiar combination of tower defense with puzzle slots. If this was segregated into levels with different enemies and challenges, it would be a fun, full game to see develop.

Fun silly concept that needs balancing.

That was actually great, really loved the concept and the execution. But the theme for me isn't quite there

Good concept but impossible to kill JUST one ennemie in the all game

Absolutely loved it.
Very intelligent merge of concepts.
Very entertaining.

love the idea of building towers through a minigame, though it felt like I was only doing a 2048 game with a cool backdrop rather than a tower defense

That was awesome.  My first thought was "Wh- how does any of this tower thing help me stop the hoards of mechanical zombies?"

And then I realized that they were more of a timer for an excellent puzzle game.  Or at least what felt like one to me.