This was another nice hardback which was discovered hurled into a corner of my yard by my postie. Like Reality's Edge, it survived two days in the rain with only cardboard protecting it, so I can recommend the books' production standards. Gamma Wolves seems almost exactly like what I am looking for - teams of 3-5 mechs ("frames") based out of a mothership (crawler), who gain experience and level up in a campaign. Heck, I've already been experimenting with pretty much an identical concept myself in 6mm for a few years now.
The focus is on the pilots and the mechs (there are no other vehicles besides the crawlers) and the aim of the author was to get some use out of his mech collection. It's a futuristic, irradiated post-apocalypse - STALKER with mechs. Arcologies (hive cities) and neutral free stations (like pirate havens) are where the survivors eke out an existence. The mecha "warbands" based out of a large crawler (landship?) explore and scavenge for salvage on months-long missions. Apparently mecha are preferred due to their 1-man crew, agility to enter inaccesible locations and also rapidly swap loadouts in the field (i.e the designer really wanted just to play with only his cool mecha toys!)
It's a sturdy hardback, well-adorned with nice mech photos. A nitpick - the post-apoc mecha sound worn and patched together and the photos show clean, high-tech gundams. They don't match the gritty fallen world the text describes (I envision more DUST style mechs). While I enjoyed the atmosphere it was a bit of a slog to find stuff - I think the book needs to be rearranged. Although 106 pages is pretty standard, it felt dense to read even though the rules themselves were not overly complex. I didn't find it user friendly and found myself constantly flipping back and forwards looking for rules. Quality good - layout poor.
Many of us have mecha from other wargames aka "frames" lying around (well, I do!) and Gamma Wolves allows you to use anything you have - going off base size - small, medium and large. I'm classing my 25mm based mecha as small, my 40mms as medium and my 50mms as large. You need a 4x4 table, a dozen d6 and Frame Cards and Pilot Cards for each model (as well as a "Contact blip" the size of the model's base). You also need tokens for Pilot Stress and Reactor stress for each model. Given you'll only field 5-6 mecha max, this seems fair. Although I still strongly think hitpoints are unecessary. I suspect lots of terrain is needed (frames have unlimited weapon range) - but you could use anything from 6mm, 10mm, 15mm to 28mm terrain depending on your mechs.
A pilot has Endurance, Manuever, Gunnery and Technical stats as well as a Pilot Value. In addition, he may have special rules - quirks and traits. A frame has Speed and Reactor stats as well as hardpoints, weight tolerance, and hitpoints in various areas (sensors, hardpoint, body, propulsion) which are a bit like a Warjack. The frame's size determines its agility (evasion) speed and loadout; obviously you have slow, powerful tank-like heavy mechs, medium mechs and lighter, faster ones which are almost power armour. There's a fair bit of stuff to cover, but given you are only tracking 3-6 mechs, it's not too unreasonable.
It's alternate activation, but not unfair activation. The side with the least models (or the least visible models) gets the initiative, and gets "passes" to make up for the deficit in models. In practice, the outnumbered side chooses when to pass and let the player with more units take successive turns. Models can snap fire (aka reaction fire) to active but accumulate Pilot Stress, which limits the reactions. In fact most actions (or reactions) accumulate either Pilot Stress or Reactor Stress on the mech itself (a bit like Battletech heat management). If machine or pilot reaches their limit, the frame shuts down.
Facing arcs is very important (good - it adds positioning decisions); while there are front/side/rear arcs, the front/rear 180 determines lock-on/vision. If a frame is deployed out of LoS, you instead move a "contact" - a marker the size of its base. The miniature replaces the contact once it is revealed. Frames have a sense of momentum - while they can sidestep and reverse, they move much faster directly forwards, making 45d turns.
Weapons have effective/unlimited range. Frames roll 3D6 - adding or removing dice for modifiers (range, rear arc attacks etc) and weapons - i.e. an autocannon might add +3D6 but a laser only +1D6. Count the rolls that pass the pilot Gunnery stat (3+ veterans, 4+ regulars, etc) as successes. If the target chooses to evade, target pilots may roll to "save" each success against their Maneuever stat to cancel the hits.
Then, roll for the hit location. (Pilots may "correct" their aim to target specific body parts by sacrificing successes.) Now, x the successes by the weapon Damage stat. I.e. the autocannon has .5 damage and the laser has 4 - you can see the autocannon is easier to spray hits onto the target, but does less damage when it hits. Sensors, hardpoints and propulsion can be damaged with the mech body containing the pilot (who can be injured) being the key component.
After evading (or suffering) hits, a frame can immediately move up to half speed. This is kind of a defensive reaction. This is also interesting.
Cool Down & War Clock
Actions can accumulate Pilot Stress tokens and Reactor Stress (on the frame). In the cool down period, pilots roll (in a similar manner to shooting) to equal their skill - each success means a Reactor Stress is removed. However, the removed Stress is deducted from the whole team's War Clock. After this, the pilot removes all Pilot Stress tokens.
Frames operating from the crawler have limited fuel, oxygen and ammo reserves. The War Clock represents the increased consumption/stress under combat conditions. Each time a Reactor Stress token is removed, it reduces the War Clock - which, when it reaches zero, means the frames all have to withdraw. This is also interesting as it adds an element of resource management - the more things you do, the faster you need to evac. Collecting salvage, not kill-em-all, is the primary victory conditions so I'd be interested how this plays out.
Missions & Campaigns
There are 6 missions, which is a little on the low side. Despite having open terrain missions, my experience suggests that with unlimited range weapons, more terrain is always better. There is a injury table for pilots, a table for experience gain, and a list of gunnery, manuever and technical talents o upgrade your pilots. For each salvage token collected, you can roll on a table to see what it was - perhaps a cool piece of equipment or rare, lucrative Old-Tech. There are rules for repairing/refitting frames and recruiting new pilots. The campaign mechanics are competent (not as cursory as most campaign systems) but are not deeply fleshed out.
I loved the setting, even though the rulebook wasn't optimally laid out. While I'm never a fan of hitpoints, they're traditional in mech games I suppose. With unlimited weapon range, plenty of terrain is needed, if you want maneuver to matter. The activation is an interesting tweak to the now-uniform alternate move (with limited reactions), and the dice mechanics are consistent and clean. The Pilot Stress kinda act as action points (better pilots have better Endurance to stress) and limits reaction fire etc. The Frame Stress (and War Clock) are an interesting resource management mechanic - the more your frames do, the quicker you use up your on-table endurance before you need to withdraw. The focus on collecting scrap > combat is interesting but I suspect it will devolve to "kill em all" in practice. There are plenty of decision points. It's a little heavier set of rules than I am personally looking for but this is personal preference, rather than flawed design.
Recommended: Yes. Even if it does not get much play, the core rules are solid and I found enough interesting ideas to make this rulebook worthwhile. It's a good way to get use out of those handful of mecha you have lying around (or wanted an excuse to buy!)