I think you have a pretty creative concept here. The lock mechanic makes for some very dynamic moves you can do. Unfortunately, I felt like much of the potential of this game was left untapped. The levels feel like they were just made to be playable, rather than puzzling. Most of the levels felt like more of a simple checklist of "hit these buttons" or "make a Mongat bridge over this open space". I think it would have been neat to have a limit on how many could spawn in each level, thus forcing you to manage your resources in order to complete the level. Without a limiter like that, it doesn't really feel like a puzzler, just a platformer with a neat mechanic. I'd also say that there were a couple spots where moving became difficult such as the level where you have to jump over another Mongat in a 2-block high corridor. One thing I would have appreciated is a zoom out function for when I needed a wider view. I think it was level 5 that was rather open. I will say I liked that the character movement felt responsive. While I would have liked the jump to be a little higher to prevent having to stack a million guys (it gets tedious) I understand wanting to keep movement snappy. I think with some finesse you could still pull it off.