Yet another game in this jam that brought me back unwillingly to my physics class (LOL)! It absolutely doesn't help that the game is literally called "MASSXVEL," but nonetheless, I appreciate the name!
I do like the puzzle-ish aspect of the game of going through your levels, it adds a bit of strategy balancing the stamina you have to finish the level while still going for score. However, I think the game may have benefitted with more levels and a level select so you could perfect a run on a specific level.
As Derek mentioned, I do like the concept, being reminiscent of arcade-style mobile games! I do find myself though having to drag across the entire screen just to get a lot of momentum; perhaps you could've made the drag across the screen less, but place a maximum on how far you can drag for that "maximum momentum launch." Some SFX or VFX on launch would have been beneficial.
The upgrades system you put in was fun to max out and see how far my ball could launch! Neat concept!