Yeah, I totally agree. I feel like the game is pretty much what it's going to be and I enjoy it as it currently is. However, I still can't help thinking about how tweaks and changes would help to elevate it further and provide more depth to the overall framework that already exists.
I've heard Dwight talk about "breadth" in the code as well as "depth." And to me, depth is the way things become available to you later in the game as you progress: play episodes, unlock Team Up, play more episodes, unlock Final Battle. But breadth would be the things available right from the start or that progress more or less independent of other features: Play an episode, Complete Training, Krang Kombos, Weapon Hurry-Ups, 1-2-3 foot combo, both MBs, etc.
The real trick, in my opinion, is to take all that breadth and not only provide different things to do, but to incentive those things through points, progress or just being an enjoyable feature. If a feature isn't worth playing or just isn't fun, then it might as well not exist.
For example, I think Training is fun, I like the way you qualify and start it, and I like the way the game induces tension with the timer counting down and the red lights flashing when you miss the needed shot. (I feel like I'm really letting Splinter down). But I'd still like more incentive to focus on progressing through it, plus it's directly linked with the perks, which are further reinforced by the "Choose Your Turtle" mechanic, which gives the entire game some extra character.
1-2-3 Foot, on the otherhand, feels likes it just sort of starts without you saying so, so if you're working on doing something else, like starting episodes or going for training or something, it feels intrusive. Like it pops up saying "STOP STOP STOP! Shoot me! Shoot me!" and then you have to decide if this semi-random feature is worth your time, and, if you haven't been focusing on building the spinner value or starting 2X PF, it probably isn't. So then it times out and goes away, you can't bring it back until after you drain (again, lack of control over the feature) so then you likely forget about it until the next time it semi-randomly starts again. Rinse and repeat. It's ultimately a shame, because completing the combo is actually pretty satisfying but as it stands if you complete it early, you don't get much value for it and it goes away.
Contrast that with the Krang Kombo, which is also not very valuable and is also a satisfying combo to complete BUT is a feature you do have control over. So when you hit the loop shot once, then quickly think either, "sure, lets try that again" or "Nah, I'm gonna stick with my current plan and if it times out, no worries." You don't get locked out of it, it will still be available if you want to focus on it, but it's also not intrusively blocking the other things you may already be focusing on.