I've never managed to finish the trijam in 3 hours (and live it's even harder). But that's no big deal for me. The trijam forces me to create regularly and test new concepts. I'm particularly happy to have found this concept this week, and I'm thinking of developing it into a bigger game.
It's true that the levels quickly become difficult. I'm going to try to make it more progressive and will probably integrate a system of tricks.
As for Construct 3, it works with visual scripting. In other words, there's the logic of the code (formulated with phrases from everyday language), but it's not code in the writing (even if it is possible, for example, to integrate javascript).
Personally, I prefer it and don't feel limited at all. The game engine is very well done, regularly updated, and I think a lot of people underestimate it.
It's a very 2D-oriented game engine (even if some time ago, updates were made to move towards 3D). Personally, it's perfect for me, as I'm not attracted by the idea of making 3D games.
And, yes, it's web-based. This may seem surprising at first glance, but in fact it also makes it easy to access on any computer (all the more so when we save our projects on the cloud). When we close the browser window, a message warns us beforehand if we haven't saved. In reality, there's not much difference from other software.
If you'd like to try it out, there's free access (with certain restrictions, of course, but it gives you an idea of how this game engine works).