We appreciate you for giving us your time to play our games and even leaving a comment below!
Regarding this issue, we're currently working on this fix. Initially we planned to implement the keyboard to select power-ups feature but then there were some bugs happening that we couldn't figure out how to solve it in time. But... in our next update you can finally select the power-ups with the keyboard! (hooray!) Please stay tuned to our next update!
Again appreciate your feedbacks on our game, it's always valuable to us :)