I'm glad I took a chance on this game despite some trepidation after the demo, although the player base on the Switch looks pretty small so far; I've been reliably getting top-20 scores on the leaderboards without much trouble, sometimes on my first try, and I didn't come in with any experience with PJM1. But I'm pushing myself to clear Tricky with no leaks on every stage before moving on to the next, which has also given me the flexibility to pursue the worlds out of their primary order, so while I've only seen about half the game so far I've also taken the time to wrap my head around what it does differently.
While I didn't play PJM1, I can see where the complaints about co-op are coming from if you're used to unrestricted movement on a static/omniscient map. Confined warping systems and map-wide division of labour don't mix, and in any case I'm glad more camera options are coming (though my complaints aren't at all about the overhead camera; it's the behind-the-back platformer camera that is too close and too low to be remotely useful). Nevertheless, I think some of the complaints about PJM2 sound like disappointment that the sequel didn't play it safely and do more of the same, rather than thinking through the design space opened up by what the new game does differently and what it contributes to the TD genre.
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My perspective here is as someone who played TDs very seriously in their prime back in Warcraft III and who still considers most of the designs from the WC3 modding scene unmatched by anything that has come along since in Flash, mobile, or PC. As such, I don't consider it gospel that TDs should have a full overhead view or that it's strictly a hindrance, particularly in a peon-based builder, to have a limited field of vision (though WC3's TDs let you click around the minimap to navigate around your limited field of view, of course, and didn't lock the camera to within a certain radius of your builder). Nor do I think it's a problem, rather than a design choice, for your ability to react to new waves or reconfigure your layout to be restricted by where you've positioned your builder on the map and which area you're working on.
With any commercially sold TDs the question for me is usually whether they add anything to the design space of the genre that I haven't already seen better executed in WC3/TFT or StarCraft II, and the answer is usually no. So I'm pleased to report that PJM2's platformer-like 3D terrain with full physics simulation makes a substantial contribution to the genre beyond what the Blizzard RTS engines or later touch-based games for Flash/mobile could handle, indeed such an important contribution that Dylan Cuthbert and the crew at Q-Games are seriously underselling it as a cosmetic or graphical thing, and I wonder whether they fully understand the implications themselves. Certainly some of the systems feel a bit unpolished and undercooked, and by traditional metrics this is a rather slim experience (not much build diversity and no real tech choices in the upgrade paths, compared to a series that excels at that sort of thing like Kingdom Rush), but the combination of the terrain, elevation, and physics has huge ramifications that scream to be further explored, and which you can already explore right now as you chase high scores and tidy up your play.
Ask yourself: how does one get better at this game? What's (in Sid Meier's terms) the "interesting decision"? Most TDs are about reading types, weaknesses, damage numbers, and so on, and budgeting around the balance of coverage versus power (building wide versus building tall), often while building minimally or inviting risk to save money or accumulate interest. There is some of that here, of course. But more than anything else, PJM2 is a game about knowing where to stand. And every major design consideration works in service of that: the speed and pacing, the penalties for collisions or falling in water, the lack of auto-loot, everything. Do you dance around a tower to upgrade it, or do you stand downslope to catch coins and currency before they roll down the hill and off a cliff? Do you build safely to shoot down aerial waves over water, or do you let them fly overland so you can loot the spoils? If you build in the back line to broaden your coverage and catch leaks, do you have a quick and consistent platforming shortcut to move back and forth and loot both ends of your setup? Do you run into the mix and loot some urgent cash while monsters are still on the path and there is a risk of getting bumped, or do you work on something else until they clear out? Do you build inwards at a high elevation or right along the path? So many of these are questions I haven't asked myself in a TD before, at least not to the same extent, and they all make PJM2 look not like the second game of an established series but the first, experimental, somewhat uneven debut of something totally new. It's underdeveloped but undeniably fresh, and we should pay it the courtesy of judging it by its own standards.
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There are admittedly interface issues. The scoring system is opaque and nothing in the game has numbers attached to it despite a clear background of calculations involving damage numbers and armour/mitigation. On Tricky you sometimes need to sit through a trial run just to see when certain alternate paths kick in; this isn't a game that's always fair about letting you anticipate threats on the first try. I can't seem to throw or activate bomb fruits with any accuracy at all. I'm mainly playing on the Switch's portable screen so the problem isn't the height of the camera or the scale of the overhead view, but the visibility of gems and coins. It seems the idea was to use the secondary platformer camera to assist with looting, with the indicators pointing you imprecisely in the general direction of uncollected items, but the angle on it is no good for that and it just gets in the way. I'd probably score higher if I made better use (or any use) of the platformer view, so I could throw fruit accurately and not miss so many coins on the ground, but I'm not going to fight with the weirdness of the camera swap just to move up a few spots on the ladder.
Oddly enough, I think this would have made an excellent concept for a Wii U game—build on the main screen, run around with a character camera on the GamePad screen. (And I'm not just saying that because of Q-Games' association with Star Fox; I really think the two-camera setup would have worked better that way.)
I'm looking forward to the patch, anyway. I'm glad the game is being actively maintained, and I find the core design very promising, although I doubt I'll jump on the DLC if one additional three-map world per pack (over two packs) is all that is on offer.