Fun and addicting! Something about the way you can draw the trampolines is very nice to do over and over. Interesting choice to make it so that the character's always jumping off a trampoline exactly perpendicular to it no matter what, without factoring in any momentum from a previous jump: makes it a bit more easy for the player. Could maybe use a bit more pizazz to it, such as foreground stars that parallax as you go upwards, or changing colors as you go higher and higher, or music or something or other, but I understand that might be against the very theme of trying to get that minimalist Vectrex style, which is done very well here.