Super Robot GURPS game.

Basic Attributes:
Size Modifier: +6 (Change as necessary.)
ST: 40; Modify as necessary depending on changes to your size modifier. +/- 10% per size
Consequently change all other stats relating to ST.
DX: 20.
IQ: 0.
HT: 20.
Thrust Damage: 4D+1
Swing Damage: 7d-1
BL: 1600
HP: 50
FT: N/A
Basic Speed: 10
Dodge: 15 (This will obviously only be applied to mech-on-mech combat.
A human with a gun can easily hit a mech, although obviously not much damage may be dealt.)
Basic Move: 20
Water Move: 5
Air Move: 0

Advantages:
Ambidexterity (Unless the robot has a weapon arm as opposed to two manipulator arms.)
Damage Resistance 10 (All except electrical based)
Dark Vision (Presumed as part of mecha sensors. Subject to modification or removal.)
Doesn't Breathe (If you have a power supply dependent on oxygen presence, feel free to modify this.)
Doesn't Eat Or Drink
Doesn't Sleep
Filter Lungs (More like air filters for the cockpit. May be removed.)
Improved G-Tolerance; 1G (Again, may be removed.)
Injury Tolerance (No Blood) (Or maybe you have "mecha blood" in your robot. Let me know.)
Injury Tolerance (No Brain) (Perhaps. Maybe your robot has some sort of "central processing unit"? Will be discussed.)
Injury Tolerance (Unliving)
Lifting ST (+5) (Subject to change.)
Payload 2 (Pilot Cockpit) (Feel free to change)
Pressure Support 1
Protected Sense (All Senses)
Radiation Tolerance (Immune) (Radiation shielding is another matter.)
Reistant (Metabolic Hazards)
Speak Underwater w/ Interface Crossing (Radio communication.)
Striking ST (+5) (Subject to change.)
Telecommunication; Radio
Telescopic Vision: +5 (May be removed.)
Temperature Tolerance: Level 10 (Pretty much, only if you get dropped into the sun. Probably also applies to temperature inside cockpit.)
Unaging
Vacuum Support

Disadvantages:

Cannot Learn (Will change if you wish for a sentient mecha.)
Cannot Speak
Electrical (Presumed. If you have another type of mecha, let me know.)
Ham-Fisted (-10)
Maintenance; One Person a Week (Feel free to change number of people and frequency.)
No Fine Manipulators
No Sense of Smell/Taste (If you somehow have a robot that can smell and taste things, let me know.)
Reprogrammable
Slave Mentality
Unhealing; Total
Vulnerability (Electrical)

Quirk:

Cannot Float

A Word On Skills:

Mecha themselves will not have skills; All skills will be given to the pilot.

However, when it comes to skills, there will be two categories; A skill used outside the mecha, and one used while piloting it.

For example: Beam Weapon is a skill, but Beam Weapon (Mecha) will ALSO be a skill.

You can use a Beam Weapon if you're shooting a Beam Weapon on foot, but if you use JUST Beam Weapon while piloting a Mecha, your roll will be
divided by HALF.

This mostly only applies to weapon and movement skills, as I doubt we're going to be picking locks in our mecha any time soon.

Equipment is entirely up to you.