Riptide GP2, an arcadey sea doo/waverunner racing game by Vector Unit in the vein of... well, Waverunner, is a digital-only racer that is well worth its asking price.
The game released rather quietly, and if not for the tiny $5 price tag, I feel that many of us achievement hunters may not have given it a second glance. I can't say that it would be worth a ton more than this, but it is most definitely worth at least that much.
You start out the game like so many other racing games, with a basic rig, a career mode to tackle, and plenty of upgrades and new rides to purchase in the game's store after earning the moolah by winning races (or coming in 2nd, or 3rd).
The gameplay loop consists of doing straight up races, 'hot lap' runs which are essentially time trials, and stunt courses where the aim is to pull off as many stunts with as much variety as possible. The tracks, sadly, are limited and re-used throughout the various stages of the career mode, but with the $5 price tag it's difficult to quibble over this. The game was originally released in mobile form, but seems to have found its true home on consoles as the addition of a real controller makes a marked difference in gameplay. I tried it on my cell phone.... and was not impressed. But I thoroughly enjoyed it on Xbox One.
My only niggling complaint about the gameplay is the rubber-banding AI. You can get quite a good lead over the guy in 2nd place, as much as 3-4 seconds, then suddenly it will rocket-boost as if by magic and be nearly right on your tail. This can get frustrating at times, but isn't insurmountable and is only really noticeable on a couple of the harder courses.
The graphics and audio are serviceable, and actually quite good considering it's such a budget title and a port of a mobile game no less. It hearkens back to Waverunner by Sega and Waverace 64. In fact, I felt quite a decent dose of nostalgia in playing through.
The achievement list consists of progressing through the career and getting 3-stars on each and every race, and buying/upgrading new rides. I believe I clocked in right around 7 or 8 hours for the full 1k, but it could be done a decent bit faster if you're super good at racing games and don't have to wait as long to upgrade your rig.
Overall this is an incredibly solid arcade racer and could have sold for twice the price. At $5 it's a steal. What are you waiting for, buy this game!