Hm. It's rare I meet anyone that gives a fart about this sort of thing these days. Lord knows none of my friends care about this sort of thing, they're too busy playing the latest RPG to see the all-important story. And cutscenes.
I sure play a TON of these myself though. I love score-based games. I could list a TON of them here... but the majority of them would be shmups, of the murderous kind. Other than those, I certainly agree on Pac-Man. To expand upon Pac-man: The biggest thing that got me about it, compared to the previous game, is how much less restrictive it is. In DX+ it ends up being purely about memorization more than anything else, because you don't really have room to stray from the pre-set course. Stationary ghosts form impassible walls basically everywhere, and the fact that a train directly follows you means that you cannot reverse direction. If you screw up on following the pre-set path, it hurts pretty hard and a lot of players will just frequently restart. In the new one, you can have many different approaches to each maze. You're not restricted to any super-specific path, which also means that you can improvise when things go wrong (which they will, frequently). The stationary ghosts are no longer impassible, they also don't drown the mazes except during power-pellet phases, but even then, the design overall still leaves you plenty of room to improvise. And you can go after fruits to switch to the next maze BEFORE clearing every single dot, which allows for different approaches to the set as a whole. Best of all: Next to no focus on memorization. I hate memorizing stuff, as I cannot do it. Also there's Extreme mode, where the ghosts once again become real threats (they aren't much of a threat in DX+, with the bullet-time thing happening). The game is also faster from the get-go. Really a great addition to an already great series.
As for other games I could mention, hmm.... most of them are roguelikes, as far as "leaderboard" games go. Isaac being the most prominent still; the game has a very, very well thought-out scoring system which supports all sorts of approaches. As opposed to something like Spelunky, where you either A: *must* speedrun the game, or B: *must* do the hyper-tedious "ghost farming" over and over and over. You have next to no options in that game, which is a shame.
Let's see... what else is there... Well, there's plenty, but most aren't the "super short runs" type like Pac-man. When I want those sorts I typically have to go to Mame for that (I have pretty much every arcade rom there ever was on this machine). Of course, those don't have leaderboards.
Typically for score-based games of other types though, I think that a max run length of a bit over an hour can work; further than that is just too long. Any shorter is fine. There are exceptions though. For long-ish ones though, the ability to save and exit during a run is a MUST HAVE, or it doesn't count.
Forced Showdown: I got really into this one recently. It plays/controls like a moba does, complete with spells on cooldown, though your basic attacks are often more complicated than they are in mobas. The big kicker though: *everything* can be dodged. Everything. The game actually ends up having almost a bullet-hell nature, due to the sheer amount of projectiles and spinning rats or whatever it throws at you at once, but it never, ever becomes literally undodgable. And you do often have other defensive moves you can use too, but they supplement the dodging rather than replace it. The other big kicker is that the game works with a TCG system. You build a deck for each character and take that deck with you into a given run. A run consists of multiple "battles", each battle consisting of 8 arenas, with the last arena being the boss. It has a mana system kinda like Hearthstone, and before each arena starts (but after the game shows you the layout and enemy placement of it) you can play cards from your hand. Everything from permanent upgrades (well, permanent through the end of that battle anyway, not through the end of the entire run), to one-off spells, to consumables that can be activated with a button-press during combat.... all sorts of creative things are here. The system overall is fantastic. What's more, each boss has a constant "presence" even when you're in the 7 arenas before actually fighting them. They all have a basic spell, on a cooldown, that does stuff. One of them can summon 4-way turrets that fire beam attacks in each direction after standing there for a second. Another summons glowing destructible orbs that create beams between them when there's more than one, forcing you to occaisionally take a moment to target them to keep them from restricting you too much. They can do these things during every arena, including the actual fight with the boss. In addition, bosses have their own decks of cards, and the same mana system (+1 starting mana per arena) that you do. They play their cards before you do, so that you can see what they're doing and respond to them. They have all sorts of different effects, from giving them new global spells for that arena, to summoning loopy minibosses, or whatever. What gets me is how creative and interesting the cards, player abilities, and enemy/boss attack patterns are in this game. And there's way more to it in terms of mechanics and such, and numerous different types of runs that you can do, too. This actually has quickly become one of my favorite games, period. I did a full review on Steam, and highly recommend it. Oh, and it uses procedurally generated arenas and things too, so it's got full roguelike elements (yet still, retains that "never unfair or undodgable" aspect that is so very important with a game like this, and I can say from experience that that is REALLY hard to manage). Very high level of polish here too. Cant recommend this enough.
Crypt of the Necrodancer: that game really works well for score-based runs of all sorts with lots of approaches. In addition, it has many different characters, each one very different from the last. If you haven't seen Necrodancer, it's a roguelike, but each "turn" has a length that's derived from the rhythm of the music playing in the background. You can only move/attack/whatever on each "beat". If you try to do something out of rhythm, the game makes a sort of "blork!" noise and your character locks up for that turn. Enemies also have a lot of unique attack patterns and visual tells to go along with it. Skeletons for example only move once every two or three turns, depending on the skeleton. On the turn before it leaps forward, it waves it's arms around. This means that you can never blame enemy attacks on "well how the hell was I supposed to know it was about to do this?!?" since each one has such a specific and obvious movement/attack pattern to it. Nice simple controls for the game too that work well with the mechanics. And lots and lots of creative items and tricks and things, like you'd hope for in a roguelike. The difficulty is brutal, though. Particularly if you pick certain characters. There's one character that dies INSTANTLY to pretty much ANYTHING. Take a hit? Dead. Miss even ONE beat? Dead. Try to get more max HP? No effect. Kinda like The Lost from Isaac except way more cruel. But there's others that are so much easier (one guy turns it into a true turn-based game where the beat doesn't matter, for instance). Scoring is based on how much gold you've accumulated, BUT, it's balanced so that you CAN still buy items without ruining your score (unlike something like Spelunky). In addition, you have a gold multiplier that increases as you kill enemies, but screw up the rhythm and the multiplier resets. It's a mechanic that works out very well. The game is actually fairly generous in terms of that rhythm, you don't have to be super bloody perfect about it like you do in pure rhythm games. One thing that does take getting used to though is that, without certain items, you *must* take an action on every beat. Standing still without activating an item or spell gets you the BLORK noise and loss of multiplier (or death for that one specific character). Effectively, your character is forced to dance, which fits the theme. Though you have one other option, which is the ability to dig through walls with your shovel (which is a fun mechanic). There's LOTS of reasons to do this, but one way it helps is that it allows you to basically stand still for a beat (you don't move when you break a wall next to you), which can let you get certain enemies into the right positions so you can go on the assault. The game works well both with keyboard (no mouse here) or a controller. I use a controller. The game isn't for everyone but I do think it's fantastic, if you can handle the difficulty of it. Enemy patterns and traps and things get pretty devious here. Bosses are complicated.
20XX: Remember Mighty No. 9? Well, this is the game that No. 9 wishes it could be. This plays ALOT like Megaman X did, right down to the controls and basic character abilities (dashes, wall jumps, charged attacks, the game controls *exactly* like X did). Same basic idea: 8 levels, with a boss at the end that you can steal a power from (and all of these powers are useful; no duds here). But levels are procedural, and there are many different items and things to be found along the way that build up your character in all sorts of ways, which keeps things really interesting. What's more, you cannot just choose any level when it's time to go to the next one; once a boss is done, you get a choice of three randomly-selected ones, so you cannot just choose the super-optimal path every time. Each boss gets harder and stronger the later in the game you fight it. A boss that's real easy when fought as the stage 1 boss can become a murderous nightmare on stage 8. The levels themselves also get harder and more complicated depending on when you visit them (hint: *don't* go to the "Agnisort" level super late in the game right now. Just... just don't). Like the old X games, this is a game that really rewards pure skill, and it absolutely fits the "Megaman" mold wonderfully. Runs tend to be about.... 40 minutes long. Pretty good length when playing for score, I say. Each stage tends to last from 2-5 minutes (later stages are longer), and you get a bonus treasure box at the end if you finish a given stage within a certain amount of time (so, more items to power-up with). There are many, many different types of runs here that you can do, including multiple types of daily runs. You are given a score at the end of each run which is based on all sorts of things. There's a lot going on with this game, and while there's some balance issues with a couple of extremely specific elements right now (most notably the boss named Eternal Star; nearly unbeatable if faced too late) the game is absolutely fantastic. I've been playing this a lot lately. Again though, it's very hard. You'll die OFTEN at first. This game also honestly makes No. 9 look downright sad. This game was made by TWO guys. Just two. Whereas 9 had this huge kickstarted budget and lots of professional developers.... and they still couldn't do it even close to right. Yet this game is extremely polished in every respect and has a lot to offer. Also, yes, it has phasing platforms in it. You know. From Heat Man's stage. They're infamous. There's even a boss that uses these. The jerk.
That's enough typing from me for now. I may try to think up others later. I'm going to avoid listing shmups though, as the ridiculous difficulty on those makes them too much for many players, and they are HUGE time-sinks due to how long it takes to even remotely learn them. Whereas games like the ones listed offer something for everyone, and even when you're losing, they don't seem insurmountable.
Also as for Savant, I have to say that one does look pretty interesting. Steam has been waving that one at me over... and over.... and over.... and over.... and over... I might pick that up.
