Stay tuned! (lol) All this little bugs that you dont like will be fixed in a new level. The worm will go faster too. But it has a limit because the more it goes fast, the more it looses stability and balance.
The problem lies with the force of the legs and the proportion of the mass compared to the thrust of the legs. I've reduce the force of the legs motor, rised the density of a block in front of it and I made it walk like 6 or 7 steps.
I think that a kind of stabiliser will do the job. But it have to know the direction where the robot is falling and then put a weight in the opposite direction. And it have to do it constantly.
I had really good issues with a mass that move toward and backward of the robot and moving in synchro with the legs motor. But it need 2 mass and I put only one, son there's only 1 leg that his "backward force" was nullyfied.
The Theo Jansen mechanism is really difficult to build without a plan because there's like 450 000 ways to build it. Theo Jansen had to put the possibilities on a computer that analysed the possibilities.....for 3 months! And only then he could build one that dont collapse and walks more normally hehe