Personally, this is one of my favorite indie games. It has a lot of pros, and a whole lot of cons.
SMASH! - You can smash pretty much anything, including many parts of the environment. Landing one of those perfect hits on the enemy, going blue, and just generally destroying everything is one of the most satisfying things in this game.
GFX - The attention to detail is superb, as seen in the environments, weapons, and "vehicles."
Story - While difficult to understand at times, I enjoyed it a lot, and though it interesting.
Weapons - There are a great many weapons available, and each is different.
Modes - There are 5 working gametypes: Solo: single player campaign, Hall: where you select and buy weapons, Grim: where you hunt flying worms, Arena: where you fight other flying machines, Hammerball: where you fight weird machines in some sort of soccer type game.
There is another gametype called Tribal Wars, but it doesn't seem to work (at least, for me).
SMASH! - Sometimes, if you go blue and miss an enemy, you might wind up outside the map.
GFX - People are really weird sometimes. The animations can be... odd.
Story - Lost in translation applies here. Quite a bit of it.
Weapons - Sometimes the chain type weapons will break. No idea under what circumstances, and it doesn't happen terribly often.
Modes - Solo: The story can be very confusing and jumps somewhat. Hall:sometimes weapons can be lost if you drop them, Grim: the idiot AI enjoy dropping bombs on your head all the time, Arena: it often pits you against 3 AI at a time, and that can make it extremely difficult at times, Hammerball: Not for the faint of heart, this is the single most difficult challenge I have EVER faced in a game. More on that later.
As I mentioned, Tribal Wars seems to not work at all for me.
On the subject of Hammerball: For the first round, you have to face a single flying mechanical lobster. Not too difficult. Second round, you have to face two. One goes for the ball while the other uses some sort of taser on you if you don't dodge it. Third round you have to face three flying mechanical flying lobsters. One goes after the ball and the other two attack you with some sort of taser.
There are 4 different ball types I have encountered in Hammerball. The first, a rock, is easy to deal with and gives you one point per score. The second is a bomb that will go off after a time unless the game ends, or you manage to score. It's worth two points. The third is a flying buzzsaw that will get angry if you hit it, and it will move around. It's somewhat manageable and is worth three points. The fourth is some sort of flying tentacle monster that will generally kill you when it appears. I would assume it's worth four points if it's actually possibly to push into the goal. Bit of a spoiler here: it looks like the final boss of the game, but can fly around.
On the subject of AI: In general, they aren't too bad. Your allies like to throw bombs though, and sometimes, the human AI like to seriously "derp out."
Overall, I think that, even with all it's flaws, it is a GREAT game. It's incredibly fun to smash the AI with hammers, flails, axes, swords, etc. The graphics are amazing, and the AI can be dealt with. For only $5 I think it's a great game, and has entertained me for hours on end.