Mate, all of what you said is actually how it is done:)

As example is this explanation concise and is the content well understood? (I intend to use those screens in the game)
http://www.youtube.com/watch?v=t2wegZx9raI&feature=channel_video_title

OK, I apologize if my comments below come across as harsh, but you need honest feedback. But, before that, let me just say that your game looks cool and the video has charming music and presentation. Now...

The first two things could have been communicated by a simple level intro level. Just let me chomp around a level, and believe me, the two types of blocks and the physics of falling will become abundantly clear without a single word of text. Just take some time to design such a level to make that clear - don't be lazy. You explaining it to me explicitly feels a bit condescending, frankly. Like, "Oh this idea of two different types of blocks...you'll never figure that out on your own! Let me explain!"

I didn't even understand why there are multiple crystals in the same place?

Why are you using a white box as an exit? Why not just a door that's initially locked, and then when you collect all the crystals it opens up? Unless you have a good reason to use something special (like "The company of myself"), it comes across as lazy.

So, in short, I really don't think your game warrants a video or even a tutorial. Just a few well-thought levels would have sufficed. If you don't want to do that, just a few lines would suffice as well - no need for a video like this.

You say that you must explain the rules of chess, and I agree. But your game is not as complicated as chess (which is not a bad or a good thing - it is what it is).

measuring very simple statistics like that can be done with steam achievements, indirectly. some games have an achievement for doing different things -- beating the game, beating a particular level, finding a particular thing, or whatever. and steam shows the % of all people who own the game who accomplished that achievement. since most games have a 'beat the game' achievement, you can get a fair sense of the game's difficulty (or length, or boringness, among other factors) by looking at what % of the people who bought the game beat the game

as an example, see this forum's own zaratustra's game eversion; its achievements on steam are interesting: http://steamcommunity.com/stats/Eversion/achievements

92% of people beat level 1
86% beat level 2
84.8% beat level 3
64.6% beat level 4
63.7% beat level 5
61.9% beat level 6
54.6% beat the game in the normal way
29.9% got the best ending

just from looking at that, it's obvious that level 4 is the hardest level, with a drop-off of 20.2% of players who beat level 3 but not level 4. this is followed by level 1 (8% drop-off) and the final level (7.3% drop-off). for the first level the effect may have to do with some people who own the game not even bothering to play it, however, so that can probably be discounted

Oh wow. That explains why so many games give me dumb achievements for completing a level...probably also just designer laziness (I've been guilty of this myself), but that is a very good use for achievements. But then again, on some platforms (iOS) you could just have it send you data every time someone beats a level.

I might soon post a tutorial-demo of my game. I hope you will like it.

I think tutorial levels/demos are fine if done well, but somethings I would be aware of:
- Avoid walls of text. Conciseness is a virtue! This also applies to sequences where it's just one text box after another. You expect me to be taking notes? Yeah right..
- Allow me to try out each concept and move at my own pace. Tell me what you want to tell me and then let me try it out for a bit before moving on to the next thing. This allows me to immediately practice the skill and make sure that I get it. Or if I do immediately get it, let me move on immediately (unless you can make the activity fun).

And this may be personal preference, but: Put the text in the level itself. God I hate clicking text boxes..."click here to move on" or "next" just dumb.

most TD games (including mine) feature a fast-forward button, or some type of speed controls; this is sort of like what you describe, except that you'd also include extremely fast ones that go to the end instantly; sounds useful but it'd only work in deterministic TD games (mine wasn't deterministic)

It would be a bit more than that, since you'd be able to go back in time and tweak your plan as well. So it's like, instant and arbitrary quick-save/load...at all points in the game.. I think the best analogy for it is keyframe animation.

Darks Souls saves constantly (through death, mistake or victory) and to me is what made it the masterpiece it is...

Beat me to it!

Demon's Souls does it too.

Yeah, I really wanna see other games explore this constantly-saving thing. Ie: Your actions are permanent...makes things potentially more interesting.

Have you played revenge of the titans? GO PLAY IT!!!

Yeah I beat it and it was awesomely fun! But again, I didn't like the trial and error. I played it way back when it was Indie Bundled, so it was in beta and didn't even mention some of the enemy quirks. I had to read some forums to figure out that you need lasers for ghosts and stuff. Also..the research aspect of it introduced another source of potential frustration if you didn't research the right things in time.

But Titans would be the perfect example of a game that would NOT work with my "scrubbing" mechanic: The game is all about high frequency actions. You gotta collect resources, aim your lasers, build a million things, etc. etc.

most TD games (including mine) feature a fast-forward button, or some type of speed controls; this is sort of like what you describe, except that you'd also include extremely fast ones that go to the end instantly; sounds useful but it'd only work in deterministic TD games (mine wasn't deterministic)

Right, it'd need to be deterministic and lack any sort of high-frequency actions (ie. no more than a dozen or two actions throughout the whole level to beat it).

What's your TD game btw?

STALKER had a tutorial?   

anyway, bring back the attract mode...

Haha yeah it was terrible. The first guy you meet basically tells you everything in one huge chunk about your PDA and stuff. I'm loving my time in STALKER right now, but man that tutorial was shit.

I take what I said back!

Haha I have nothing fundamentally against these things... but they should only be there for reference. The game should still stealthily teach (convey?) the actions in-game.

megaman is also a great example of level design teaching gameplay (see http://www.youtube.com/watch?v=8FpigqfcvlM for egoraptor's gushing about the series)

I saw this the other day on one of my buddies' Facebook pages. Everyone reading this thread needs to watch it. Conveyance is such an amazing technique in action games, and if you pull it off right, you absolutely do not need a tutorial.

Yeah he pretty much sums up what I was trying to say. In hilariously correct fashion. The thing with Zero is another great technique: Show another character doing something awesome rather than telling the player.

megaman is also a great example of level design teaching gameplay (see http://www.youtube.com/watch?v=8FpigqfcvlM for egoraptor's gushing about the series)

to tackle the problem of having SO MANY KEYS ON A KEYBOARD, do what most flixel games to and have the main controls need to be pressed to activate the game! Fathom was great because you had to press Z and X to start, so your fingers were already on the keys by the time you get to the gameplay. No more instructions are given to you (for reasons to do with the story) but you get a hang of what you can do right away, the first screen practically screams "go right" at you. Everything is designed to get you to do what the developer wants you to do, without forcing you.

Not saying it isn't without flaws but it is a fantastic basis to work from to incorporate an intuitive tutorial into your game. I am following very similar design philosophies for my own project, using players' own inquisition to teach them the controls.

That egoraptr should be like required viewing for allll the designers

Those aren't really games as much as they are pyramid schemes of spam.

I've been thinking a lot lately about pure exploration and documentation games – like Pokémon Snap for the N64 (I only played the demo at the store once, so this may not be a perfect example). How do you make sight-seeing in a game more interesting?

"Extreme Photographer" is an idea I've been kicking around a bit. Tornado chasing is pretty exciting - make a game about that! Get as close as you can to the tornado, take a photo, and the closer you get the more money you get. You can also do dangerous animals, volcanos, geysirs, hurricanes, etc. etc. So you'd roll around in various vehicles trying to get that perfect angle. Not sure about the details, like what kinda graphics you'd use, but that'd be the basic premise.

Oh, and for timeline displays: may I direct you to a video of a time-travel game called Achron? Notice how the timeline has lots of different graphs that measure different quantities (in order: time machine use, damage taken, damage dealt, units built, and total resources). It also allows you to bookmark specific times and return to them later. I think this is a good model to start with.

Yeah, I tried to play Achron...but really did not get it at all :-/ Does anyone understand that game?

But I agree - the timeline display they have is something to look at. You'd probably want to have graphs for your money and core-damage ("core" == thing you're defending), etc.

Honestly from the OP's idea though, without something to limit that it would become boring very quickly, if any mistake can simply be rewound that game would just be incredibly easy.  Mabe take the "Sands of Time" approach and have killing enemies of different powers fill up a rewind gauge

That's kinda like saying if you allowed infinite rewind in a platformer it would become boringly easy.... see Braid So yes, you'd have to make sure to balance and design the game so that it's not boring, and thus it would become a different type of game. More of a puzzle/debugging game with TD-like mechanics rather than a TD game per se...

Most allow you to call waves early (often for a reward), and to place towers during waves (which is often the key to beating them), so I don't think this is really a problem. A simple fast forward key should do it.
What you describe would be more like a tower defence themed puzzle game, really.

True, what I'm describing would be more like a puzzle game. And it would allow you to create really devious wave-patterns that perhaps you wouldn't do in a normal tower defense game.

I just started playing Defense Grid and the fast forward is quite nice, so perhaps that's a simpler solution..