Excellent
The combo I personally prefer is the Big Laser, High Caliber Cannon, and the Cooldown Reduction.
Very good game, seems like something I would even be willing to buy. Almost.
I love the graphics, the sound, and the amount of upgrades. I love that the later weapons seem more powerful and the legs/armor get more awesome without breaking the game.
I only have a couple problems with the game.
While there are some shoulder weapons that can ignore the walls, I don't like that unless an enemy is lower in the terrain than you, they can still hit you, wall or no wall. It's not that bad, seeing as how you shouldn't die from just that factor, but it does get annoying.
You should really put medal 'targets' up somewhere for each mission. I have no clue what time I need to beat in the main missions, and almost all of the side missions I can't tell what I need to do to get a medal at all. Do I need to not take damage, is there a certain time, what?
The Nano Repair. It's a good, useful special to have. My only complaint is that either A) it needs to give health based on the type of enemy killed, not a flat amount, or B) it needs to give a bit more than it does - not a lot more, but maybe an additional 5-10 flat/percent hp - when you kill a tank.
I honestly don't see the point of the Legs Rail White. The heaviest I can make the mech is 165, and that's only 5 over the legs Heavy White, and I'm using weapons that really don't go with each other that well, as well as the shield special component, which can be useful, but there are other specials that are just as useful and don't weigh 50 tons. Maybe if some of the weapons weighed more, maybe if the legs didn't hold as much, or if there were some other factor to make being able to hold 200 tons necessary, I could understand the Legs Rail White. As of now, though, they really serve no purpose, other than you must have thought that the leg part was needed to keep the amount of legs the same as the previous sets.
The display in the top left. I know it shows me my health, I know it has a compass, I know it shows me my cooldowns, but for the love of god I want a way to move it or make it disappear. I keep clicking on it when I'm trying to shoot something that happens to have wandered on screen from that direction.
All that being said, this is a very enjoyable game, and I look forward to more games like this.