I'd say this game could be truly fun if only it wasn't so... cumbersome to use. For example, if the character accelerated faster, or if there was an easier way to create boosters, for example by pressing down the left mouse button (making the character not move while you're holding) and then create a booster with the appropriate angle and force depending on where the cursor is once you release the button. Momentum-based gameplay and RGMs with boosters can be really fun, you just have to make it easier to build them in the first place.