Who's up for some free fantasy tennis?

I could be wrong, but I think my very first Mario game was Tennis for the Game Boy, in which you don't play Mario at all. He's the umpire, a bristling presence in a high chair, eyes glued to the ball. Unless there's a spin-off I've missed, Mario himself wouldn't take up a racquet till Mario's Tennis on the, ergh, Virtual Boy. At the time, I had no idea who he was. Why did the umpire have a properly drawn face, while the players themselves looked like stickmen in Wimbledon whites? Why did he always seem so happy when he declared my serves out of bounds? Why did the crowd always agree with his decisions? I hated the man immediately.

I'm wasting your time with these nostalgic ruminations because I've been wasting mine with Thwack from Jon Topielski, a nifty indie tennis game with an immediately addictive browser-based demo. Rendered in chubby 3D with the Godot engine, it uses parallax to create a sort of wobbly drone's eye perspective, which is surprisingly non-irritating. The players have suction cup feet, which doesn't really impact the proceedings but makes every match sound like you're popping bubblewrap under your desk. Essential! I mean, 5/5.

It's a simple game - move around with WASD, swing with space - but you can exert reasonably delicate control over the angle and speed of the ball based on your direction and momentum when you strike. It allows for some familiar tennis gambits - he writes, having not played actual, flesh-and-blood tennis for decades. You can rush the net to panic the other player, always at the risk of them calmly lobbing the ball past you. You can try to drive them off-centre by aiming for the opposite corner, then send the ball mockingly in the other direction. Or you can miss the ball completely and feel like a fool.

Tennis is widely perceived as a "casual gamer" subgenre, associated with licensed titles and (literally) throwaway motion controls, but it's actually one of the industry's primordial archetypes, as ancient as the text adventure. One of the very first home format games, Atari's 1972 hit Pong, is a tennis sim in all but name. It's a little bizarre to boot Pong up and realise that the original core thrill has carried through to modern tennis sims unchanged. It's that touch of ambiguity around each swing - you're always figuring out the underlying physics, and when the ball finds its way perfectly past the opponent's defences, it feels like sorcery.

In the full version of Thwack, yours for a piffling $2, there are difficulty modes, five additional opponents, local multiplayer and cool hats, written in order of ascending importance. Each opponent has a themed tennis court - the Snowman's court is covered in snow, of course, while the Ghost's wraps around spookily, so that when you fire a ball out sideways, it reappears opposite. Mario would probably rule that a foul, but screw him, the smug little git.