I really appreciate that you took the time to try the game out, and I agree with most of your points.
I could conceivably make the tutorial chambers into their own levels in some regard, although that will likely increase the overall number of levels both in the single-player and co-op campaigns (I would have to figure out how to do that on the co-op side as well.) I'll admit I'm running low on level ideas, and I have very few boss ideas, so that work is a slog right now.
I'm also planning on adding a few more elements to the chambers overall, such as launchpads, lava, and electric fences. I have next to no artistic ability so I have to rely on others for sprites for the most part, and pretty much anyone who is willing to draw for me without getting paid a fortune up front is busy with other stuff a lot of the time.)
Hopefully things will start coming together in due time, though. I'm not a big forum guy, and I don't know how well I would fit in with the Jams you mentioned. I typically don't like signing up for new forums.
Again, thanks for your feedback, and I am hopeful others will do the same. I'm always open to new ideas.
Yeah no problem, I enjoyed playing DZ.
As for future levels, I think what I was trying to say was that I think you should try to do unique and interesting things with the mechanics the game already has rather than adding new mechanics just to add to the level count. Level design is arguably the most important part of this kind of game. You said you're running low on ideas, which sucks, I know that feeling. To find inspiration for level design I ask a lot of "what if...?" "I know it's absolutely ridiculous, but what if...?" kind of questions, then sketch out levels based on those ideas, play around with them, see what works and what doesn't, and adapt them from there. Some ideas will stick, others won't, and others might make you ask other what if questions. I find this method a lot of fun.
Another way to think about level design is discussed in that talk I linked. Think of design not as inventing something new, but uncovering truths that already existed in the universe. Game design is asking the universe a series of questions, and curating the results such that they form a cohesive product. As an example, I really fucking love The Impossible Game's level design. For one, the game as a whole has good design (at least in my opinion), but two, I feel the level design explores every single possible combination of the level elements. All the block formations, spike formations, patterns, and everything like that feels fully explored. And in addition, Level 2 (gravity flipped) and Level 3 (disappearing blocks) feel like the 2 most important "gimmicks" to explore. I've probably grown to appreciate this since I've sunk so many hours into the game, but watching a video of all the levels should give a pretty good idea. The universe is SO SIMPLE and has SO FEW ELEMENTS, but the level design makes every section of every level feel unique and deserving of its existence in the game. I also find this way of thinking of level design to be fun. (Maybe I just find level design fun? not all the time anyways) Link:
http://www.youtube.com/watch?v=vW8nXTzroosI felt that interesting platforming both involving and not involving spikes was unexplored. I can think of a ton of tiny situations like jumping around a pillar on a narrow walkway, jumping diagonally over a pit, utilizing walking on the sides of spikes, landing between rows of spikes, avoiding jumping into ceiling spikes, etc. I think I just love intricate jumping sections of games, haha.
As for other communities, I'm not a big forum guy myself at all, but recently I've found a lot of IRL people also interested in games and game development to talk to, and I feel like that's been really beneficial. It sucks to develop games proverbially in your mom's basement. Plus game jams are a great way to toy around with stuff and try out skills you don't normally use, as well as hone existing skills. I highly recommend Ludum Dare, there's a lot of people (on average 1400 every jam recently) and they give very positive and useful feedback, both in comments on your games and in their IRC.
Wow, wall of text v2. Wasn't really expecting that.