The best way I could describe his playstyle would be to picture a zany, Looney Tunes-esque character. Off the wall animations, lots of squash and stretch, a very crazed fighting style.
His signature spin would likely be his Neutral Special, having virtually no starting or end lag, like in his games, which can give him more air time, extend combos, and bring foes closer to him. A very versatile attack.
His Side Special would have him pull out his Wumpa Bazooka and take an aiming stance. A reticle would appear on screen that you could freely aim, and tapping the special button fires fruit. Exiting requires pressing the A button or jump/shield.
His Up Special would likely be the Arrow Crates, which would appear under him to shoot him upwards. I imagine you could use this twice before hitting the ground.
His Down Special could be a Crate Cycle. Cycle between a Metal, TNT, and Nitro Crate. TNT crates would explode three seconds after being touched, Nitro crates would instantly explode upon being touched with heavy knock back, and Metal Crates would do tons of damage if dropped from midair. Using your spin near a crate will send it hurdling in the direction you're facing.
Final Smash would utilize Aku-Aku, a mask spirit and Crash's friend and guardian. This could grant Crash a power boost and invincibility to knock back.