@aurel300
Thanks for your detailed feedback! I tried to introduce the mechanics using the first few levels, though I have to admit that it was not clear enough. As a result, placing a time machine in the first level is not really a good attempt.
It was intended for players to try the machine themselves and obtain a brief understanding of the machine. During their exploration in level 1, they would probably meet the time reversion in 10 seconds. And then there would be a test for these basic mechanics in level 2. I thought that players can feel like they're clever when they figure out all these things by themselves. However, the fact is that I should have made it clear,
This also holds for the orb collecting mechanics. In level 4 there is a ball naturally running towards then orb which is on the top platform. Then player have to push another ball to collect orbs. I tried to use this level to tell players that you can use anything to collect orbs. (When it comes to orbs with blue objects, I originally designed different colors of orbs but I didn't make it to implement due to a lack of time.)
Indeed the freezed blue objects are a little strange considering the whole mechanics. As far as I know, you can use this feature to push the big blue box in level 7. (It was actually my first solution to this level.) The point is that even though the time is limited to 0-10 second, objects do not always go in loops, since the unseen former loop is undetermined. I also planned to further exploring this mechanics if there was more time.
By the way in level 6 you can directly jump to the orb if you push the top part of the box and perform a jump on it. The moment feeling that "Oh I'm more clever than the designer!" is great. So didn't lock the rotation of the box as in level 7.
Indeed the physic system need to be optimized. I should have done it better.
After all, thanks for your advice! ^^