You can't turn left while boosting because of how the keyboard buffer works. My advice is to get a controller and use JoyToKey to play. It works around the limitations of the keyboard.
The demo has enough content to allow a player to make an informed choice about buying the full game, something which many demos today fail to provide. I'd buy it but I don't have a credit card. As for the game itself, I enjoyed the combination of leveling up defenders between battles and upgrading them on the battlefield. Gives more value to passive bonuses. The level design is good, accounting for all the units you would have at each point and making the better positions fairly obvious without giving them away completely. The writing is excelent, plot isn't needlessly convoluted and the characters actualy have some personality.
Seemed to easy until I reached level 7 where the difficulty shot from "Barely there" to "What the hell! How am I supposed to do all this!" It would be a lot more doable if the targets weren't so damn small and the bullets were a little more predictable. Doesn't help that the controls lagged regularly for me.
Good start but could be better. Some actual vehicle variety would be better than each one being a straight upgrade (lets say having a lighter vehicle accelerate faster while heavier ones are slowed down less by collisions just to begin with). Being able to control your gun's firing would also be good (early on, the zombies are small the the terrain is flat enough to build up plenty of speed, the bullets would be more useful later when dealing with the big zombies on uneven terrain).
I felt that the game was too easy but I played rogue and went for the debuffs first thing. Mass Confusion is probably the most overpowered ability the rogue has. The 50% attack reduction is more like 90%, my guys blocked more hits than they took throughout the entire game. The enemies felt really underpowered, I only had like 6 battles where either of my guys died and only lost both of them once and even then it was only because I wasn't keeping track of my guys' health. It's a good game, the difficulty just needs tweaking.
Unbalanced difficulty much? The first form of the boss is much harder to beat than the second and third ones (you don't even need to move to beat the second one, just park yourself in one of the gaps between the mines and keep on firing). The final form is difficult only due to the random nature of it's shots.
Give us the option to turn off the automatic selling of equipment. Sometimes I'll lose an item that buffs one stat when I pick up one of the same type that buffs a different stat by one more point, often one that is already buffed.
I don't see Greek mythology used in a lot of games and even when it is used it tends to be done rather badly but this game uses it well. The puzzles are very easy but that's okay becuase I figure the idea of this game is to see what happens rather than being overly challanging.
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New update just released completely revamped the combat system and overall game balance! Give it another try!